Problem on live install - Please help

Hello,

I've upgraded to 3.0 following the instructions. After that, I've installed the anti-splogs plugin, I've uploaded the new multi-db files & I've tried to upgrade the blogs.

But now, I have no more access to anything : I'm stuck with a "error establishing a database connection".

Could you please advise on the best way to solve it asap ?
I have checked everything, but I'm still stuck with this.
here is the link : http://blog.enseignons.be

Thanks for your quick help,

Benjamin