[AccessD] Access2010 vs Access2007

Hi folks.
I bought a new dev machine with Win7 and Office2010 32-bit. It installed the
Access 14.0 Object Library. The "default file format" in Settings is Access
2007.
My app runs on my client's Win2008 R2 Server and all the workstations run
Win7. However, their Access references point to the Access 12.0 Object
Library. As a result, when I upload my app to their server and open it up I
get a warning message that "some of the features may be incompatible", even
though I haven't used any of those features.
Do I need to scale back to 12.0 on my side or upgrade the client to 14.0?
And how would I do that?
Thanx,
Darrell