WordPress 2.7 is so slow! Tried going back to 2.6… still slow.

Like a lot of other people after upgrading to 2.7 my site’s admin and actual webpage is VERY slow. It’s so bad that it takes at least 5 minutes to make a post that should take no more than 1. Half the time the post times out before it uploads an image or asks me to log in again. I wouldn’t mind the slow admin (although it is a huge headache) but the fact that my actual site is loading as if it were on 56k is awful. I tried searching the forums and found no solutions. I tried going back to WordPress version 2.6.5 and even that was still slow. I even updated my server from PHP4 to PHP5. What can I do to fix this? Has this problem been resolved yet or am I going to have to just wait for 2.7.1?