I replied by e-mail to lanvasquez already. Here was my answer:
"Don't worry - most probably you didn't converted from R372 to R373 before
the flash
Here is what you have to do:
1. When it's turned off press and hold the * + # and press the red button
(start). You should enter bootloader. Even if the screen is completely
white or crapped - no worries.
2. Connect your phone with datacable
3. Use the flashing software and flash this:
http://www.e398mod.com/content/view/506/30/4. After the flash is complete your phone should be working fine. You may
need to remove the battery once after the flash (only if it do not turn
on)
5. Now you can flash the Elektro firmware"