I had my phone S-OFF with alpharevx beta. Used CM7 -stable for couple days but decided i wanted to go back to all original. I first RUU my phone with the RUU_Buzz_Froyo_HTC_WWE_2.22.405.1_Radio_188.8.131.52 4H_184.108.40.206_release_160191_signed.exe file. Boot it up, made sured it runs, then did what is instructed below here;
To be able to do this you need HTC USB drivers installed. Install the HTC pakage, reboot, uninstall the HTC-
Sync software, keep the drivers! reboot PC again.
Power off your phone. Plug in your USB cable to phone. Press volume down and powerup your phone. After it
settle navigate down and choose fastboot option.
1. Unpack these files to your c:\fastboot
2. Open up your windows command promt (WinVista/7 users rightclick choose run as Administrator)
3. in command promt type CD\ then press enter
4. then your should be in C:\
5. type cd fastboot
6. then you should now be in dir C:\fastboot
7. Im bored to death typing, look below. Beware of each command ends with enter. After success, reboot.
C:\fastboot>fastboot oem mb 9C068490 1 30
C:\fastboot>fastboot flash hboot hboot_buzz_7225_1.01.0001.nb0
sending 'hboot' (512 KB)... OKAY
writing 'hboot'... OKAY
Files needed (Windows version): megaupload.com/?d=UO9L74I9
Works perfectly for me.
* NOTE: Im not responsible for your phone if you brick/kill it. These steps worked for me!