Stop error 0000007a after /3gb switch -- tried to repair with CD

*Please note that my personal memory on this issue is not superb... I may be getting some technical details wrong.*

I'm running XP Pro, SP 3 and I tried the switch and my machine didn't like it, (I did make a backup of the boot.ini) so at first I tried safe mode, no cigar.

Next I tried the recovery console (boofcfg I think?) but it said that I couldnt use that command until I ran chkdisk. Ran chkdisk, and it found something (don't know what). After it was done I typed EXIT and restarted. Still got the stop error.

I guess I didn't understand the chkdisk thing, so after that, I just decided the best thing to do was repair from the CD. All was going well, but when my computer needed to restart to finish the process, I ran into the same stop error. I even got to see the "windows starting up logo" that was preparing the next step to the repair, but soon the BSoD came.

By the way, I have a brand new HDD, so I hope any errors chkdisk found are just bad logical sectors or something. I ran the diagnostic from startup (the long version) and everything looked good.

halp!

EDIT*******
My specs:
Dell Inspiron 1520
XP SP3
Intel Core 2 Duo
T8300 @ 2.40 GHz
2.39 GHz, 2.99 GB RAM
Physical Address Extension
(WD Scorpio Black SATA - 320GB, 7200rpm)