Import function doesnt recognize pictures

Hello, i just started using PSE yesterday and imported my 6000 Pictures.

Everything worked fine except for one folder. PSE just doesnt import the pictures in there.

I tried removing the folders inside the specific folder or renaming the folder but everytime i try to import the pictures, PSE scans the folder and then says the files are either not supported or already in the database.

In the folder are "normal" jpg-files taken with the same camera as all my other pics. There is nothing really different about it.

I hope someone can help.

Thanks a lot