huge issue with OS X 10.4, not allowing me to open or copy.

A few issues this morning with some huge deadlines on my back today.

My PowerBook G4 is not allowing me to copy any files to the hard disk.

This includes unzipping any zip or rar files. I'm not even able to do simple copies either. I tried opening and adding to my itunes library with no luck either. Anybody have an idea on what I can do now?

How full is the hard drive? If there is room left it might be a permission issue.

If that is the case, I would run Disk utility and repair permissions. Just a guess but can't hurt.

tried that

I have run the disk utility and no luck.

I have aproximately a 75gb hard drive and have about 8gbs available.

Not enough alas.

A hard drive requires some 15% free space in order to work at its best. Perhaps there are somethings that could be trashed, and then empty trash?