@markta: burn the firmware in a good quality CDR - not a DVD, not a CD-RW, nothing else, and at 1x speed.

Burn the images files with the proper program that understand the MDF and MDS. In case the software asks, burn in mode2, not the usual mode1 (this shouldn't be a problem with MKIV, only with MKIII, but better safe than sorry). Don't just burn the two files.

After burning, check if you see a lot of files and folders inside the CD.

You should be safe then.

__________________
My BMW: Photos