copy from Mac OS X and paste to kde apps

I've been a long-time linux user and have started using a Mac. I'm getting X11 setup using macports and have installed (ported) KDE. I would like to copy and paste back and forth between Mac OS X apps and X11 apps. I am generally able to do so by following this FAQ: http://developer.apple.com/qa/qa2001/qa1232.html (Q: How do I copy and paste using X11 for Mac OS X? Q: How do I make copy and paste work with other window managers?) However, pasting into kde specific applications with middle-click is not working (e.g. in konsole). I can paste into other X11 apps, e.g. xterm and emacs, even when those apps are launched from within KDE using the kwin window manager. Any suggestions? Thanks, Jonathan