Yup. I'm a Noob...
I was trying to install Cyanogen Mod and I ended up wasting the bootable image on my US T-mobile Defy.
I can get to the Boot menu, but it will not accept Cyanogen because it has the wrong signature. I tried a Factory update.zip from here on the forums, that didn't work either.
The phone had the latest from T-Mo. I believe it was Froyo.
HELP!... what are my options now?, besides getting a new phone!?