Major WordPress Issues..

Since I upgraded to WordPress 2.5.1 nothing but major trouble. My host provider even shut down my site for awhile. I can not figure out what the problem my be. They were telling me I was using to much CPU. Something in the wp-admin/php-a-ajax was writing to many files to my site. The something freaky is happening when I try to post a entry. My save and publish buttons are flashing..