Do you still have the threaded tDOM-0.8.0 dlls? I was trying to install openacs into my aolserver on Windows XP yesterday. When I checked the server log, I got the same error you had - "tDOM wasn't compiled for multithreading." If you still have the files, can you email it to me at email@example.com? Also, did you just put all the dlls into lib directory under aolserver root directory?