The error cause a Dr. Watson error or a general protection fault. See Release Notes for McAfee NetShield v4.5 Anti-Virus Software for Windows NT and Windows 2000 Service Pack 1.
See the links to "Network Associates Support Solution ID: nai18383", "Network Associates Support Solution ID: nai18427", "Network Associates Support Solution ID: nai2482", "McAfee Support Solution ID: nai7440", "McAfee Support Solution ID: nai14238", and "McAfee Support Solution ID: nai25225" for information on this problem.
McAfee recommends that you experiment with increasing the number of milliseconds contained in the ScannerThreadTimeoutEx registry value. This approach increases the length of time available to the engine for recovery before the exception occurs. To determine the optimum number of milliseconds in your environment, you must balance the risk of receiving a Dr. Watson or GPF and a failed scan on the one hand, with the inconvenience of devoting additional time to the scanning of very large files, on the other hand.
To get around this, increase the ScannerThreadTime variable in the registry. It is under the HKLM\SOFTWARE path. I cannot comment on the full impact this may have. Obviously it may slow things down as the antivirus software may take longer time to scan files but this may only be applicable to large files. Test on a non-critical machine before implementing.