Slow wordpress

Hi,

I have made a wordpress site. It’s at: http://www.differenz.dk/

Sometimes when I visit it, it’s really slow and sometimes it’s “normal”.

I can’t set up Super Cache due to safe mode on the server. Can anyone tell me what I can do? I tried removing some of the more unnecessary php calls from header and footer.

Any thought on how to troubleshoot the problem? Is is serverwise or not?

Here are the plugins I’m running:
All in one SEO pack
Contact Form 7
Flutter
FLV Enabled
Google Analyticator
Google XML sitemaps
List categories post
Page links to
Simple Google map
TinyMCE advanced
TinyMCE valid elements
Useful 404’s
Use Google libraries
WP admin quicklinks

Hope anyone can help, thanks.