I've been running beta2 for the last couple of weeks, and have now several times run into a weird lockup condition that I have not seen in 2.5.3 or earlier releases. The system gets into a state where it doesn't seem to want to deliver mouse/pointer events to any X11 applications --- the most response I get to a click is a quick double beep, and sometimes not even that. Keyboard events are still delivered fine. Switching input focus to another window is a bit tricky, because you can't do it via pointer, but command-digit works. AFAICT the only way to get out of the problem is to quit and restart X11. Unfortunately I cannot give a reproducible way to cause the problem. I think it has generally happened when I am returning focus to X11 from another Mac application, usually Safari --- I have a Safari window in front of several X11 windows, click the yellow button to minimize Safari, click on some X11 window to start working there, and suddenly things are all pear-shaped. But it doesn't happen every time or even often, so there's probably some additional trigger condition required. Or maybe there's some sort of timing-dependent race condition? It only seems to happen when I do this fast without thinking, so I'm not 100% positive I didn't mis-click somewhere I didn't intend to, but in any case a lockup isn't expected. Anybody else seeing this? regards, tom lane