I've been noticing something weird about my daily screencasts - sometimes, the movies captured by IShowU get "lost in translation" when I bring up QT 7.6.4 to do the video export (for embedding on the website). I never had this happen back in Leopard; it's got to be some kind of library issue with Snow Leopard. The symptom? The video just drops in the embedded version about halfway through. I have no idea what's causing it, but I can work around it by exporting the MP4 file I create for uploading to places like YouTube.
I could start using QuickTime/X, but its really, really limited in its export facilities. It is to QT 7 what iMovie '07 was to iMovie HD. With any luck, Apple will recognize the mistake (as they did with iMovie) and release a decent update to QT...