C5 Dashboard eat 100% CPU when a single user loads it.

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I'm running C5 5.4 on apache 2.2.16 in fcgi mode and PHP 5.3.3-7 with Suhosin.

I've got a site that loads perfectly when I'm not logged in to the dashboard- under 3 seconds. When I log into the dashboard an apache process pops up and burns 98-100% of one cpu while the site just dogs along. I think its ajax calls or something, but I have no idea. Has anyone else experienced a similar issue? Any pointers on how to start troubleshooting this?