neouto.. in case the issue returns.
I had the same problem accessing my admin after the changes designed to make wordpress faster (all the urls changed from https:// to http://), mine got so slow that it always timed out before loading.
I eventually went back to using the https:// urls and now have no problems. I access through 3 different computers and have noticed that the 2 running win2k are the ones that have problems with the new urls (one with firefox, the other running opera), the one running windows xp has not had issues.