>For information purposes, the application that we're using was upgraded from VFP6 SP5 to VFP9 SP1 by doing a recompile in the project.
>Wonder if this is the correct way to "upgrade" the source codes?

May be if you aren't using the few things that require editing, like use of keyword "ARRAY" in Local or Declare statements, or Group By in SQL statements which doesn't conform to stricter rules, or label captions beginning with a "=", which is now interpreted during instantiation. Few smaller things like that.

If it compiled right, you'll probably be fine, most of these are caught at compile time.