I am in the same boat!
I installed and had ‘Sociable’ working fine last night and was able to work with the setting just fine.
I went to show a collegue how it works this evening and when I access the settings I get a plain blank white page. I look at the source for that blank page and I can see lots of code so I’m thinking something key must be missing.
I checked to see if the problem was browser specific but both Safari and FF Mac give me the same result.
So I thought maybe it was server OS specific (the first installation was on a Windows server) so I installed the plugin on a site I had on a Unix server with a very different theme and while it works on the pages & posts I still can’t access the settings.
Funny thing is why did it work last night but not today?At least I got it setup the way I wanted to on that first installation before it blanked out on me.
And by the way I’m using WP 2.9.1 everywhere.