Can't crop thumbs, chmod problem?

[miss.trulla]

Due to a server problem all folder permissions have been reset to 755 on my site recently. I went ahead and changed the albums and edit folders back to 777, so uploading new photos works just fine. The only thing that's not working is cropping thumbs. I tried to find how the Stramm files need to be chmoded, but the installation file doesn't mention any folders or files in particular that need to be chmoded.
The actual problem I'm having is that the crosshairs to select the part of the photo you want as thumb doesn't show up anymore.
The files are still exactly the same as before, the only things that's changed were the folder permissions, so I'm a bit at a loss here and any help would be much appreciated!

[Joachim Müller]

but the installation file doesn't mention any folders or files in particular that need to be chmoded.

There is a section in the docs that is dedicated to setting permissions: http://coppermine-gallery.net/demo/cpg14x/docs/index.htm#permissions

[miss.trulla]

Thanks for your reply. I knew how to chmod folders, I was looking for a list of what specifically to chmod, especially the Stramm files. If those mentioned in your link are all that need to be chmoded, my problem is a new one altogether, because I did chmod them all.

[Stramm]

Clear cookies, reset your browser as much as you can, allow JavaScript
If that doesn't help reupload the modpack, ie the cropper folder (maybe something has been messed up there).

If you can upload files and thumbs get created, then the custom thumbs tool should work, too.

[miss.trulla]

Re-uploading the files did it, thanks for the tip