Undo libc6 upgrade in testing

[Frank <hugelmopf@web.de>]

Hey list,

I am running testing and did an upgrade today, which included libc6 and quite 
a few other packages.
Now I have problems with some non-Debian libraries, that I use for work, and 
the backtrace looks a lot like problems with the new libc6. Is there any 
connection between the new libc6 and the gcc4.0 transition? Because I compile 
these libraries with gcc3.3.

How can I downgrade libc6 to the previous state? I tried with apt-get:

	apt-get install libc6=2.3.2.ds1-22

(which was the previous version) but it tells me, it can't find this version 
anymore. Is there any way of reverting the upgrade, without downgrading to 
Sarge?

Desperately looking for help,
Frank