All,

I am supporting a legacy application writtein in FoxPro 2.6a for Windows. The application has been running fine for years with the usual occasional problems that can happen with FoxPro in a multi-user environment.

However we had a problem recently that defied explanation and I wanted your thoughts on it.

We recently upgraded most of our desktops to Windows 7. It appears that our FoxPro for Windows application works fine on it. However, a user recently began having a problem printing a report for certain records. We tried all the usual troubleshooting efforts. We deleted the user resource file, reindexed all the tables etc. None of this worked. We tried from other machines and the same thing occured. Renaming the report file would solve the problem only temporarily. Tried updating print drivers, using postscript drivers, using universal drivers etc. Again the report would still hang for certain records.

Now the report in question did have function calls in some of the field expressions. I tried creating a new version of the report without any expressions or function calls at all and this cleared the problem in testing. So I tried to put the expression/functions back on the report one by one to isolate the problem function. But the behavior was never consistant and I could never isolate it to just one function call or expression.

After a few days of trying to trouble and resolving to re-write the report and just do all the expression formatting and function calls in the query leading up to the report call, the problem just dissapeared. All of a sudden every data record was printing fine. Other problems in the system seemed to be resolved too.

Now to verify our assumption that the issue was data related, we had the data restored from a day when we knew it was bad, and sure enough we could reproduce the problem with that data set. We looked at that data set and saw no obvious corruption or funny characters.

It's a mystery that I would still like to solve. I don't like when a problem just appears and dissapears with no explantion.

Thoughts?