It should not crash like that - there must be a problem there. I have had over 2500 files on the Pending Files list and it opened - slow, but it opened. I would suggest that you try the bug fix version or re-install the one you have. Bug fix version is available by responding to:
http://forums.comodo.com/help_for_v3/please_tell_us_if_v3_didnt_work_for_you_here_you_can_get_a_test_version_look_at_the_poll-t16546.0.htmlFor future reference, the procedure for clearing the Pending Files list is
Purge (Removes files that are no longer on your hard drive)
Lookup (checks with Comodo's database for known files)
Submit (Sends unknown files that you want checked to Comodo for analysis - you may want to avoid submitting really large files)
Remove (This just clears the file list - if you are happy that the files on it are ok, then just remove them)