running office 2003 and Office 2007 (problems with database)

[hp]

Hello,

I have a workstation with both Access 2003 and 2007. I am having issues
with opening our 2003 database which is the version that works fine. It seem
that 2007 is getting in the way some how. When I click on a button on my
switchboard it pops up with this error

The expression On Click you entered as the event property setting produced
the following error: object or class not found.

i havent changed anything to the VB so i don't see why it does not work in
the 2003 version.

thanks for any help