VERY slow after upgrade

I upgraded from WordPress 2.0.4 (MySql 4.0) to 2.2.1 (MySql 5.0) and now my site is extremely slow. The only plugin I’m using is wp-cache.

From my home page’s source:

<!– 25 queries. 29.365 seconds. –>
<!– Dynamic Page Served (once) in 29.365 seconds –>
<!– Cached page served by WP-Cache –>

I tried exporting the database and then re-importing it, but that didn’t change anything. I also tried optimizing the blog db in MySql – didn’t work. The db indexes seem to be there. Connectivity to the db server is fine and other web pages served up by the same web server come up instantly. There are no errors in the Apache logs.

Any ideas on what this could be or what else I can try?

Thanks.