'04 330i with Navigation system. Recently updated to 2013 dual DVDs for the navigation maps. Now my screen locks up and I cannot do anything except listen to the radio. The firmware is 4-1/91. I've seen other posting on other forums about updating to 4-1/00 as the latest. Problem is I'm not sure /00 is equivalent to 100 or "zero". Also, it appears the part number is a discontinued part number even if is correct. Am I barking up the wrong tree pursuing a firmware update? Has anybody else had this problem?