I don't believe that is inherently true as a matter of upsizing. Access 2007 will
recognize and tread all functions the same, with one exception:
If you have a missing reference, all bets are off.
From any code module, choose References from the Tools menu. Check to
see if any have the word MISSING next to them. If so, you need to remove or
replace those references with ones that exist in the Office 12 environment.
If that's not the issue, then post the function that doesn't work. If it's not an issue
with references, then there isn't enough to go on here.