Can't build project in DEBUG mode

Today, I got this strange error when trying to compile the Portal project:
Unexpected error creating debug information file 'C:\Documents and Settings\kharris\VSWebCache\KHARRIS\obj\Debug\SchoolNet.Portal.PDB' -- 'C:\Documents and Settings\kharris\VSWebCache\KHARRIS\obj\Debug\SchoolNet.Portal.pdb: The process cannot access the file because it is being used by another process.'
I have no explination for it, but when I closed VS.NET and deleted the KHARRIS folder from VSWebCache, everything worked -- cool.

Also, deleting files was painfully slow. As it turns out, this happens when you have a lot of files in the recycle bin. I emptyed it and reduced the Recycle Bin file size to 1%.