OK, I have had this problem for a while now and I have been trying several things so far.
The problem is that Photoshop gets stuck (or hangs, appears to be not responding) when it starts up.
I tried to fix it by:
- removing the TWAIN plugin
- resetting the Photoshop to factory settings (deleting the settings file)

So yeah, I was wondering if you have some ideas (besides reinstalling everything).
For further information, I have Windows 7 :V