Sorry to resurrect this thread, but I didn't see a solution, and I have the same problem from a Windows XP SP3 machine. I'm using the -323 with two 1-TB WD Green drives for external backup storage, and currently the backup files are around 100 MB, one for each of four backed-up drives. Deleting each file takes about an hour, if I remember correctly, which is way too long. Other than the deletion problem, this backup system works well.
The file system on the -323 is EXT2. Would reformatting to EXT3 solve this problem.
Thanks for any help.
-Mike