I don't know how well X2 has been running for you or for how long, so I am only guessing at these ideas.
Did you follow
Suz Shooks Tip and Tricks when you installed it?
Maybe corrupt cache files: read this part of Suz's site:
008 Cache and Related Files
The locking up on start up almost sounds like it is trying to catalog your photo images, can that be set to look for these at random periods of time or if you have a lot of new files, like Check again in 30 days?