Insuffient(sp) server space

Running 1.1 Ghz, XP-Pro 1GB memeory, updates current.
When I map a drive, or share a folder on an NTFS partion,the message “insuffient server space’ pops up when I rry to access from this machine or a networked client. This just recently started. the share shows up on the network. I just cannot access it. I have uninstalled all recent activity. I have reread everything on shares/permissions and probably missed the clue.