My buddy's E90M3 (built date: April 08, came with 2008.1 disc) required "software update".
a. Pop DVD in
b. iDrive message- shut off for about 5 mins thing.
c. Shut off and turn back on about 10 mins later and it worked fine.
I'm sure now that I didn't need any software update because my car came with 2009.1 disc already (built date May 2009).
PAST: 11 E70 X5M | 08 E90 M3 | 08 E92 335i | 03.5 E46 M3 | 99 E36 M3