apt-get upgrade UNSTABLE mistake ...
 

Ello,

I did an upgrade with unstable mirrors in my sources.list...

I'm sure he upgraded libc6 , gcc g++ and that kind of stuff, is there a way to go backward and do a "downgrade" to the stable things again ??

thx !

Debian backports
 

You could try here:
http://www.backports.org/

But be prudent in the future.

By the way, you might be interested in this package: apt-listbugs:
"apt-listbugs - Lists critical bugs before each apt installation"

Cheers,
Sylvain.