Odin Stuck On NAND Write Start? topic

I rooted my phone and wanted to flash back to stock so I can update with the OTA and re-root, but I downloaded the zip for the AT&T tar files and everything seemed to pass MD5 checks and went okay, but as soon as I hit Start, the program just continues to say NAND Write Start for over 20 minutes, and won't flash, how do I go about re-trying this without bricking my device? It's still plugged in atm in download mode.