>Are any data compatibility problems between VFP6 and VFP5? I mean, if I modify table/database structure in VFP6, or even create new table from scratch there, will it pose any problem working with this data from VFP5 application?

So far, the only thing that's bitten me is when I used new VFP6 specific functions in a stored procedure; that's by no means the result of exhaustive testing, though.