Why does it take ages for linux to delete Windows Thumbs.db files (30 minutes or so)?

I do not know where to post this, this is maybe related to multimedia stuff but definitely a hard disc or system problem.

I had large amounts of multimedia files on external drives (usb hds) used on a Windows 7 PC. Typical windows creates Thumbs.db files in the directories of those multimedia storages.
The files itself are very small (about 100kb) but when trying to delete them on linux (having the same USB harddisk plugged in or mounted the network storage) via the rm command or over dolphin (even when skipping the trash) it lasts ages! for it to finish deleting those files. No kidding, sometimes i wait for an hour. But only those files!
No other problems with the hard disks so far.

What is wrong with them? Why does linux need so much time to delete a windows file, there should not be any dependencies to check or something?