I am running WP 2.9.2 and had Atahualpa 3.4.6 running perfectly. I tried 3.4.7 and it didn't run. I went through the motions as advised and got 3.4.6 back running again. Whew! However, my WP Dashboard looks almost like an ancient command line interface. It has lost all its formatting.
I have now tried the 3.4.9 upgrade, but it doesn't run well either, with my site having all sorts of formatting issues. I was able to again resume using 3.4.6, but the Dashboard is still messed up.

I would be glad to just keep running 3.4.6. I just want my good ole Dashboard back! Help!

What happens if you switch to the default theme

The Default theme runs fine, while the Dashboard still looks messed up/ no formatting.

I should mention that I also tried turning off all Plugins. I am currently running w/o Plugins.

if you switch to the default theme and the dashboard is still messed up, then it is not a theme issue. You might want to try reinstalling the wordpress modules.

download a new copy of wordpress and replace everything but the wp-contents folder and wp-config.php

Thank you very much, jd! That did the trick, and I learned something new!

I made a small donation in your name. I appreciate the help!