James,

I had exactly the same problem. If some of the controls (for example, the Calendar control) don't generate the error, but other do (like the Common Dialogs), then I think you're missing the License in the registry. There's a FAQ under Third Party ActiveX which describes it. Do a Find under the Edit menu in the Register Editor for Licenses. Look for one that begins DB4C0... If it isn't there that's the problem and you'll have to get the License from Microsoft tech support.

Good Luck,

George