Hi guys, I have this issue too and was curious if replacing display did in fact (and is in fact) the solution to the problem and if it's a DIY fix...thanks.

(my post on e46 fanatics) Just bought a 2003 330CiC with all the toys, and the navigation is a little strangely behaved. It can take between 15 and about 40 minutes to start up when the weather is below 50 degrees (f). The blank screen flickers a bit, but displays nothing. Radio works fine and unit is responsive to button selections. With no warning, Navi starts up, displays BMW splash screen (OEM s/w and navigation map discs), displays "accept" message and then works as if nothing was amiss. Took a look in the trunk, and there is no power/pilot light when the blank / flickering screen is seen. Dealer flashed with some sw update but no effect. Anyone have any ideas? Thanks in advance. Ken.