Slow loading site: CI or bad coding?

[eluser]codex[/eluser]
Hey all,

I'm currently working on http://www.graffr.com (it's about Graffiti/streetart). I think I did a pretty ok job on the coding, but somehow it's slow as hell. I moved the site from one server to the other, thinking it was the server that was slow (I moved because of other problems), but on the new server I get basically the same poor performance.

The profiler isn't revealing any odd numbers, they're actually pretty good I think (< 1sec). Also benchmarking produces quite good numbers (10ms or so) per page. But still, a very basic page like the signup page takes about 8 secs to load. Needless to say that's very long. Even cached pages take forever!

Any ideas on what could cause this slow performance? I'm puzzled...

PS: I have indexes on the DB in case you might be thinking of that