Today I downloaded the mobile version and registred it. But after the latest sync (complete collection incl. back images) I can't start the program anymore. I get the following exception:

DVD Profiler Mobile.exe
MissingMethodException

by DVD_Profiler_Mobile.frmStartup..ctor()
by DVD_Profiler_Mobile.frmStartup.Main()

Don't know details about the error, but have you tried to remove it and the uploaded data and re-installed it already?
Maybe the .Net Framework is somehow corrupt. I'd uninstall and reinstall that as well...

Hey guys, I was having the exact same problem.  It just started out of the blue.  I have the program and the data files (DB and images) stored on my 1GB SD card.

I finally decided to do a hard reset.  Once everything was reinstalled, I tried it again, sure enough, same problem. 

Then I remembered I had the files on the SD card.  This time I manually erased all the DVDProfiler related folders from the card. Then I reinstalled and resynced.

Everything seems to be fine now.  I still don't know why it happened, but that's how I fixed it.  I'll watch to see if it happens again.

EDIT: FYI this was on a Treo 700w - Windows Mobile 5

Ken