Have you tried to recompile your VBA project? Go into VBA editor and click on the menu option Debug > Compile Project. If it bombs out at the same line I recon you have some sort of namespace conflict. In this case prefix it with the object library as shown below
Thank you for the answer. I got this error while trying to compile my code (only with ArcGIS 10, it is ok with ArcGIS 9). I do not have access to arcGIS 10 until Monday, but I will try your suggestion!