Problem Running Disk Defragmenter

[Adam Arents]

I'm running Windows XP, and recently I've run into
problems trying to defragment my hard drive. When I run
Disk Defragmenter, it gives me this
message: "Defragmentation of (C:) has been aborted due to
inconsistencies that were detected in the file system.
Please run CHKDSK or SCANDISK on (C:)to repair these
inconsistencies, then run Disk Defragmenter again."

I've run the Check Disk utility, but it still gives me
the same message. Any ideas on what is causing this
and/or how I can fix it?