Means the new one -03 is a new revision. The question now is (and maybe a BMW mechanic may know that) you can mix 02 and 03 revisions?
In my car for example (what is a 8 cyl) it was not allowed to mix revisions. Two where defect and they had to change all eight of them. Your local BMW dealer should maybe know, if not some pro in the forum here.
Your second problem with putting D in and nothing happend I think is not injector related. More likely a software problem. Allways imagine that your car runs on kinda WindowsXP system. Windows XP because all the DME software of BMW is quite beta, is rockold, was never realy finished and likes to hang and play crazy at least once a year. Reseting the system (reboot -> lock car, walk away with the key (if not the car still reads the key and it wont work)), let it sit for at least 15min usualy reboots the system).