Environment: SIngle server farm - Windows 2003 - MOSS SP1
I found another server with the same "access denied" error in the crawl logs. So I applied the Loopback fix but then another error:
The system cannot find the path specified. (Exception from HRESULT: 0x80070003)
After searching the internet, I found the solution. You have to make sure the "gthrsvc" folder exists under your search account's Temp directory. Then restart the search service.
CMD> net stop osearch
CMD> net start osearch
Then run full crawl. Worked for me.
I think this is another side effect of one of the recent server patches. This particular server has been around for a while and the crawls never had a problem until now. Going to check the rest of my MOSS servers now...