Some time ago (around 2.3.2rc4) I complained of seeing random freezeups in X11. You asked for an Activity Monitor sample. I just saw it again, for the first time in months, so here is the sample. I am currently running 2.3.3.2 (xorg-server 1.4.2-apple42). The symptoms are that no X11 window responds to typing or mouse, and the X11 window title bars do not react when you move the mouse over them. However, you can still pull down menu items. I found out that the Quit item still works (even producing the helpful little "are you sure you want to quit?" dialog). Hope this is helpful. regards, tom lane Sampling process 17400 for 3 seconds with 1 millisecond of run time between samples Sampling completed, processing symbols... Analysis of sampling X11.bin (pid 17400) every 1 millisecond Call graph: 1797 Thread_2507 1797 start 1797 main 1797 mach_msg_server 1797 mach_startup_server 1797 _Xstart_x11_server 1797 do_start_x11_server 1797 server_main 1797 X11ApplicationMain 1797 -[NSApplication run] 1791 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] 1791 _DPSNextEvent 1789 BlockUntilNextEventMatchingListInMode 1789 ReceiveNextEventCommon 1786 RunCurrentEventLoopInMode 1786 CFRunLoopRunInMode 1786 CFRunLoopRunSpecific 1776 mach_msg 1776 mach_msg_trap 1776 mach_msg_trap 4 __CFMachPortPerform 4 PullEventsFromWindowServerOnConnection(unsigned int, unsigned char) 3 CGEventCreateNextEvent 2 CGSGetNextEventRecordInternal 2 snarfEvents 1 CGSDispatchDatagramsFromStream 1 CGSDecodeEventRecord 1 CGEventCreateFromDataAndSource 1 CGEventCreateFromDataAndSource 1 _CGSGetPortStreamInline 1 mach_msg 1 mach_msg_trap 1 mach_msg_trap 1 CGEventCreate 1 CGTypeCreateInstance 1 CGTypeCreateInstanceWithAllocator 1 _CFRuntimeCreateInstance 1 __CFAllocatorSystemAllocate 1 __CFAllocatorSystemAllocate 1 GetCurrentEventQueue 1 pthread_self 1 pthread_self 2 0xffffffff 2 _sigtramp 2 _sigtramp 1 CFRunLoopRunSpecific 1 __CFRunLoopModeFindSourceForMachPort 1 CFSetApplyFunction 1 __CFRunLoopFindSource 1 __CFRunLoopFindSource 1 __CFRunLoopTimerRescheduleWithAllModes 1 mk_timer_arm 1 mk_timer_arm 1 __bzero 1 __bzero 2 AcquireEventFromQueue 2 _NotifyEventLoopObservers 2 HIApplication::EventObserver(unsigned long, OpaqueEventRef*, void*) 2 HIApplication::HandleActivated(OpaqueEventRef*, unsigned char, OpaqueWindowPtr*) 2 SetMenuBarObscured 2 ShowBar(unsigned char, unsigned char) 1 MBarDraw() 1 ShowHide 1 _ShowHideWindows 1 WindowData::PrepareForVisibility() 1 HIView::Render(unsigned long, CGContext*) 1 HIView::Draw(short, OpaqueGrafPtr*, unsigned long) 1 HIView::DrawComposited(short, OpaqueGrafPtr*, __HIShape const*, unsigned long, HIView*, CGContext*) 1 HIView::RecursiveDrawComposited(__HIShape const*, unsigned long, HIView*, CGContext*, unsigned char, float) 1 HIView::RecursiveDrawComposited(__HIShape const*, unsigned long, HIView*, CGContext*, unsigned char, float) 1 HIView::SendDraw(short, OpaqueGrafPtr*, __HIShape const*, CGContext*) 1 HIView::DrawCacheOrSelf(short, __HIShape const*, CGContext*) 1 HIMenuBarView::DrawSelf(short, __HIShape const*, CGContext*) 1 HIMenuBarView::DrawTextTitle(MenuData*, CGRect const*, __CFString const*, unsigned short, CGContext*, bool) 1 CGContextSetRGBFillColor 1 CGGStateGetFillColor 1 CGColorSpaceCopyDefaultColor 1 CGColorSpaceGetDefaultColorComponents 1 CGColorSpaceGetDefaultColorComponents 1 ResetMenuBarWindowFilter() 1 +[CICGSFilter filterWithFilter:connectionID:] 1 -[CICGSFilter initWithFilter:connectionID:] 1 +[NSKeyedArchiver archivedDataWithRootObject:] 1 -[NSKeyedArchiver finishEncoding] 1 __CFBinaryPlistWriteToStream 1 __CFSetGrow 1 __CFSetGrow 1 ReceiveNextEventCommon 1 SendEventToEventTarget 1 SendEventToEventTargetInternal(OpaqueEventRef*, OpaqueEventTargetRef*, HandlerCallRec*) 1 DispatchEventToHandlers(EventTargetRec*, OpaqueEventRef*, HandlerCallRec*) 1 ToolboxEventDispatcherHandler(OpaqueEventHandlerCallRef*, OpaqueEventRef*, void*) 1 FindWindowAndPartFromMouseEvent 1 FindWindow 1 FindWindowOfClass 1 FindWindowCommon(Point, OpaqueWindowPtr**, short*) 1 FindPlatformWindow 1 CGSFindWindowAndOwner 1 _CGSFindWindow 1 mach_msg 1 mach_msg_trap 1 mach_msg_trap 1 _NSHandleCarbonMenuEvent 1 FindWindow 1 FindWindowOfClass 1 FindWindowCommon(Point, OpaqueWindowPtr**, short*) 1 FindPlatformWindow 1 CGSFindWindowAndOwner 1 _CGSFindWindow 1 mach_msg 1 mach_msg_trap 1 mach_msg_trap 6 -[X11Application sendEvent:] 4 CGSDeactivateCurrContext 2 _CGSSetLastDeactivated 2 mach_msg 2 mach_msg_trap 2 mach_msg_trap 2 _LSSetMetaApplicationInformationItem 2 _LSDoSetMetaApplicationInformation 2 mach_msg 2 mach_msg_trap 2 mach_msg_trap 1 -[X11Application activateX:] 1 ActivateTSMDocument 1 MyActivateTSMDocument 1 _HaveKeyboardInputMethodOrModeInputSources 1 _CreateKeyboardInputSourcesArray_Mutable 1 OSAtomicCompareAndSwapLongBarrier 1 OSAtomicCompareAndSwapLongBarrier 1 -[X11Application(Private) sendX11NSEvent:] 1 +[NSEvent mouseLocation] 1 +[NSScreen _zeroScreenHeight] 1 _NXGetScreenRect 1 CGSGetDisplayBounds 1 lockDisplay 1 CGSUnlockShmemLock 1 CGSUnlockShmemLock 1797 Thread_2603 1797 thread_start 1797 _pthread_start 1797 CAPThread::Entry(CAPThread*) 1797 HALRunLoop::OwnThread(void*) 1797 CFRunLoopRunInMode 1797 CFRunLoopRunSpecific 1797 mach_msg 1797 mach_msg_trap 1797 mach_msg_trap 1797 Thread_2703 1797 thread_start 1797 _pthread_start 1797 server_thread 1797 dix_main 1797 Dispatch 1789 select$DARWIN_EXTSN 1789 select$DARWIN_EXTSN 7 ProcImageText8 7 ImageText 7 doImageText 7 RootlessImageText8 7 RootlessStartDrawing 7 xprStartDrawing 7 xp_lock_window 6 CGSLockWindowRectBits 6 _CGSLockWindow 6 _CGSSynchronizeWindowBackingStore 6 mach_msg 6 mach_msg_trap 6 mach_msg_trap 1 xp_synchronize 1 _xp_synchronize 1 _xp_async_dequeue 1 pthread_cond_wait$UNIX2003 1 __semwait_signal 1 __semwait_signal 1 WaitForSomething 1 BlockHandler 1 QuartzBlockHandler 1 NSPopAutoreleasePool 1 NSClassFromObject 1 NSClassFromObject 1797 Thread_2803 1797 thread_start 1797 _pthread_start 1797 xpbproxy_x_thread 1797 xpbproxy_input_loop 1797 pthread_cond_wait$UNIX2003 1797 __semwait_signal 1797 __semwait_signal 1797 Thread_2903 1797 thread_start 1797 _pthread_start 1797 glvmDoWork 1797 pthread_cond_wait$UNIX2003 1797 __semwait_signal 1797 __semwait_signal 1797 Thread_2a03 1797 thread_start 1797 _pthread_start 1797 DarwinProcessFDAdditionQueue_thread 1797 pthread_cond_wait$UNIX2003 1797 __semwait_signal 1797 __semwait_signal 1797 Thread_2b03 1797 thread_start 1797 _pthread_start 1796 select$DARWIN_EXTSN 1796 select$DARWIN_EXTSN 1 __CFSocketManager 1 __CFSocketHandleRead 1 CFRunLoopWakeUp 1 mach_msg_destroy 1 mach_msg_destroy_port 1 mach_port_deallocate 1 mach_msg 1 mach_msg_trap 1 mach_msg_trap 1797 Thread_2c03 1797 thread_start 1797 _pthread_start 1797 _xp_async_thread 1796 _xp_async_dequeue 1796 pthread_cond_wait$UNIX2003 1796 __semwait_signal 1796 __semwait_signal 1 _xp_frame_draw_cb 1 draw_frame 1 draw_titlebar_text 1 ATSUDrawText 1 TTextLineLayout::DrawText(unsigned long, unsigned long, long, long) 1 ATSUDrawGlyphs(ATSGlyphVector*, unsigned long, unsigned long, FixedPoint*, CGContext*, Float32Point*) 1 RenderGlyphRecordArrayWithCG 1 CGContextShowGlyphsWithAdvances 1 draw_glyphs 1 ripc_DrawGlyphs 1 ripc_DrawGlyphs Total number in stack (recursive counted multiple, when >=5): 9 mach_msg 9 mach_msg_trap 7 _pthread_start 7 thread_start 5 __semwait_signal 5 pthread_cond_wait$UNIX2003 Sort by top of stack, same collapsed (when >= 5): __semwait_signal 7188 mach_msg_trap 3587 select$DARWIN_EXTSN 3585 Sample analysis of process 17400 written to file /dev/stdout