phpMyAdmin has been extremely slow for me [both the DH installs and one I did]. Most requests take ~ 1 to 5 minutes to complete [those being SHOW TABLES and such, nothing SQL intensive]. My apps don't seem to have the same latency issues.
I know PMA does a lot of meta look ups for schema / table overviews, maybe this is the issue?
My server is snagglepuss:winnie, btw.