[AccessD] ADO function problem. Set Cnn=CurrentProject.connection Fails?

I am having a strange problem on one PC.

Application is (A2k) running in Access XP. The following line of code gives
me a strange error, indicating a problem with the DLL.

Set cnn = CurrentProject.connection

It says Run-Time error -2147220999 (800401f9) Automation Error Error in the
DLL

I replaced the DLL from a PC that the application is working but same issue.

Application compiles without a problem.

Anyone know what this is.