I have program installed in Prague which I can't administrate on location because I'm in different country. Program is distributed over internet.
Users reports error like "can't open table xx.dbf" and "can not locate xxx.dbc". It is about most frequently used table. There is no rule and error appears from time to time on different options so I can't resolve problem. Reindexing and validating database doe's not help. Error appears again but noone knows when. There is no network. Language is VFP 6.0 SP3.

Doe's anyone can help? Which tools to use to resolve problem?

Thanks in advance.