???
Googlelabs says 22 / 100
http://pagespeed.googlelabs.com/#url=http_3A_2F_2Fwww.tagungshotels.de&mobile=false
Webpagetest.org says 83/100
http://www.webpagetest.org/result/110514_GT_KWMV/
Page Speed Online is using Page Speed 1.11 while WebPagetest is still on 1.9 (I’ll upgrade as soon as the SDK is available). The scores aren’t comparable across versions and they added a whole bunch of new rules.
Don’t get too carried away with the score though, I’d worry MUCH more about the basics (the grades right below the score). Particularly the keep-alive and gzip checks - those are just server configs and don’t require any code changes and make a HUGE difference.