The problem has been resolved!!!

As suspected, we found bad data. This experience emphasizes the importance of error checking routines in programming. You just can't assume you will always get good data. If error checking routines were used, we would not have had to spend these past few days looking for the problem. Not only that, but the system was partially unusable during this period.

The company that developed this system is no longer in business. I guess we know why!!!

Mike, thank you very much for your assistance. I notice you help a lot of people here. Good job. I'll try to help others as well.

Keith