I am having a nearly identical problem. My classic asp pages work until I use one of the Application, session or server objects, then I get the '8002901d' error as well. Checking Event Viewer / Windows Logs / Application, I have the following entry each time the page is executed
"Error: The Template Persistent Cache initialization failed for Application Pool 'ASP.NET 1.1' because of the following error: Could not create a Disk Cache Sub-directory for the Application Pool. The data may have additional error codes.."
These asp pages worked fine until I installed Vista Service Pack 1, then all fail. I've already lost the restore point to before SP1 was installed, and uninstalling SP1 did not resolve. I've tried every suggestion I could find on the web for IIS 7 setup, but nothing so far has fixed this for me.
HELP!!!