Problem moving files from shared folders.

Im having a strange problem that only came about recently.

Whenever I move folders from my shared folders ( Users/public/public documents for example) it copies the files instead of just simply moving them. The folders are on the same hard drive/partition so there does not seem to be any reason it should start doing this. I dont know what I could have changed on the computer to cause this to happen either. it is quite a frustrating problem however because large files take a while to transfer when they should be moved instantly.

If anybody could help I would appreciate it.

Thanks