how to proceed? i can't redownload the update, i can't back it out, i can't do anything with apt-get/dpkg without it telling me i ned to run dpkg --configure -a first, which comes up with the exact same results..

An ubuntu version? Where did you get this package from? It didn't come from EB4 or Debian.
You probably have two versions of libc6 installed now. I had an issue like this with another package that I accidently caused on my own. I had to find out exactly where that package installed to, delete all files, and then edit apt in several places to get rid of any trace of the package. Then I was able to install the package.
However, with the culprit being libc6, this baby is depended by lots of other packages, so removing it straight out would probably not be a good idea.

OK, I figured out a way to get my dpkg/apt functioning again --

rm /var/dpkg/triggers/libc6

umm.. yeah, an ubuntu version.. that's what eeebuntu used for 3.0 ... (this is in Eeebuntu 3.0 support .. )

the system is functioning, so i assume that the dpkg was breaking somewhere that was prior to getting it started upgrading, or post getting it all the way upgraded .. although i haven't rebooted yet, so that may be rough. hopefully there will be another libc6 update that won't be broken, before then.

Oh, right, you're posting in the eb3 section. My bad.
Let's hope you have all of libc6 installed, otherwise, some things may not work as well as expected.

i'm not a master of apt and dpkg, for sure .. is there a way to find out what the prior ver of libc6 was, and force it to reinstall that ? it now thinks it has upgraded the package, but i'm not positive that it has or not ..

I do know dpkg calls upon several files in /var/lib/dpkg/ to retrieve info on the package. In particular, status and info/* . You can try a bit of hacking around in this directory to make dpkg think that libc6 does not exist, and then install the libc6 deb package from here or find an earlier version. Have a go at it remembering to backup the files you change just in case. This was the path I took when trying to repair a version mismatch with a partially installed package.
I'm no expert either, so proceed with caution.