Colin,
>Thanks for your answer. My second post said that it works perfectly in VFP7.
Are you working with the exact same set of data in both cases? It would appear not.
When you use the LLFF to write to an existing file, they will not make a file SMALLER. If your file had 1000 bytes and you only write 600 bytes to it you will put new content into the first 600 bytes of the file and the last 400 bytes will be whatever they were before.
If you want to add to the file you need to FSEEK to the end before starting to write. If you want to overwrite the file, erase it first.
>Is this a bug in VFP6?
>
>If so this client cannot afford to upgrade to VFP7 at the moment. What the ramifications of calling a VFP7 executable from VFP6?