Since moving from a DEC Alpha server to an NT server, we've been experiencing some unusual problems. The details are:

We have a network based FoxPro application. The application has approximately 50 Windows 95b PC client users. It is written in Visual FoxPro 5.0 and uses a 5.0 dbc container to house the database tables. The database size is roughly 1 gig with most of this data in just a 2 tables (5 cdx, dbf, & fpt files).

We recently moved the network file share for this database from a DEC Alpha server to an NT 4.0 server (service pack 5). Since that move, we have experienced intermittent client PC "lock-ups" or "hangs" in random areas of the application. The application either releases if the user waits long enough (30 to 60 seconds for a normal 1 to 3 second function) or the VFP application errors out. The errors are almost always one of the following three:

Error 1705 - File access denied
Error 111 - Cannot update cursor
Error 41 - Memo file missing or invalid

It appears that error 111 is happening when the user is attempting to update the tables. Error 41 is happening on table opens and error 1705 on SQL selects.

We have double checked our NT security permissions and ruled that out. The error seem to happen in groups (ie: several clients in a short period of time) and then all clients will run OK for a period of time. The error occurrences are more common during the day when usage of the application is at its highest.

Lastly, we have this same application at another site that is comparable in size (ie: number user clients, database size, NT 4.0 file server, etc) and do not have this problem at that site. One of the couple of differences between these two sites is the version level of McAfee virus software on the client PC's. The site that is running good uses the current version 4.5.0 version of McAfee on the PC clients. The site with the problem occurrences uses the McAfee 4.0.3 version. We have doubled checked the McAfee configuration to insure that we are scanning only "Program Files" and not the Fox data files (dbf, cdx, & fpt). But we are still suspicious that McAfee is the mix causing the above errors.

Does anyone have any past experience with McAfee causing "lock-ups / hangs" with Fox database applications? Do you have any other ideas of things we can check on the NT server? This problem has been going on for a week now and our users are getting frustrated, and so is the small group of us who are troubleshooting the problem!

Your quick response is really appreciated.

Regards ... Joe Pawlowski