The After Effects CS5 (10.0.1) update is available:
After Effects CS5 (10.0.1) update: bug fixes and RED features After Effects region of interest (http://bit.ly/9ex5Cf)

This update fixes a lot of bugs, including some crashes and a problem with AIFF audio. After you've installed the update, please let us know whether it works for you.

If you have any problems with the update, or if you have bugs to report after you've installed the update, please let us know through the usual channels:
feature requests, bug reports, crash reports, and sending feedback After Effects region of interest (http://bit.ly/93d6NF)