Sorry if this has been asked before, and I'm still looking through TFMs,
but I added something (I think aviplayer) from unstable to my nice boring,
working stable (Debian potato) system and in the process broke xdm since I
forget to tell it not to upgrade other things.  

I haven't yet found a good way to downgrade with apt-get.  is there any?

dpkg would do it, but its pretty manual.  Have I any other options?

I just want to go back to my nice old X (3.3.6?) and working xdm.  Going
forward with a dist-upgrade looks like 300MB on  a 56k modem (ick).  Any
wise tips on how to (quickly!) pull it off the potato CDs?

(This is where my old but nifty Exabyte is not helping -- Didn't figure
I'd need to back up all that, just configs!)

Thanx

-- 
"To misattribute a quote is unforgivable." --Anonymous