Instance crash periodically, file locked by another peocess?

Win NT 4.0, 8.1.6.0.0 single instance.

My instance has been crashing about once a day for the past couple of days. Every time it happens, it says the control file is locked by another process. Oracle support told me it might be because the AntiVirus or 3rd party backup utility lock the file. I am pretty sure there was nothing like that running at the time of crashing. It is indicated in the alert file that the CKPT process failed to lock the control file. Once I restart the instance I have to do a recover database. It will run for another day or two. Has anyone seen this before? Is there any way to tell which process is locking the file?

Thanks
Bob Received on Wed Aug 06 2003 - 21:31:41 CDT