I've had better luck using Gateway's exploit and Launcher_GW.dat (renamed as Launcher.dat, of course).
Waiting for the system to load the SD card titles also helps.
The bottom screen should flash white, and then swap to redNAND (modified emuNAND) afterwards. If it never flashed, or it hangs after, even 30 seconds, go ahead and reboot.
helped out a lot, especially with the bat file.