The obvious forensics to look over are the dsmerror.log and Windows Event Log, where the latter in particular should have some info. The "The requested operation could not be completed due to a file system limitation" error can occur where the file system is tight for space, and heavily fragmented. Have your Windows administrator take a look at the system and its disk space, to clear out or move unneeded stuff. Also, reboots are known to put into effect latent system changes which someone put into place, so beware that.
Richard Sims at Boston University