Hey dude !
Sorry about your troubles. It looks like an indexing problem...
(I'm currently changing the indexing system, and those kind of problems won't happen again with the next version of the program)
Here's how to fix it:
1) click the help button and choose "locate my coollection file".
2) delete the "Tmp" folder you'll find there (you need to close the program before, otherwise deleting won't be allowed).
3) start Coollector again.
If that didn't fix the problem, please send me your coollection file so I can look at it.
Your coollection file is named "MyCoollection.cool" and is located in the same place as "Tmp".
And here's my email address: hector at coollector dot com.