Well, went back to the drawing board. Created a new VirtualBox server running Ubuntu 10.04 and installed Fog 0.32. Having run the install again, I realized that I had to have deviated from the standard installation instructions at least twice over username/password instances. Noting this, I did a trial run and was able to successfully do everything PXE-related (Memtest, Register, etc.). I followed the instructions for Uploading an image and was able to do so on the 1st try.
With this success in hand, I went back to the physical server and removed Fog following the instructions here:
[url]http://www.fogproject.org/wiki/index.php/Uninstall_FOG[/url]
Reinstalled Fog on physical server and voila! Happy image uploading. 🙂