Lost delay write back

On a peer to peer network there is a Toshiba laptop Pen4 1.99 that is hard wired to the router and when a shared file is saved to the main desktop the following message comes up “Lost Delay Write Back” then an error message comes back DISK FULL. Theother computers on the network do not experience this problem, all are running Win XP Home edition. This condition does not always exist it seems that it only happens when there are several files open. This laptop has 256 Mg ram.