Odd file folders showed up in library

Yesterday I was doing a little cleaning up, and backing up my files. I noticed in the Library folder there were about 100 file folders named with symbols among the other files. There was nothing in them, and I put them in the trash and then ran disk utility on the HD, and then erased free disk space.

Everything seems ok, but I was wondering if this is a warning of some sort, or a result of something that I need to be aware of. I'm getting ready to install Leopard.

TIA!