Yeah I have experienced this issue myself and can reproduce it fairly easily now. My M3 is a March 08 production, and I had the software update done in December 08.
Before the update, I noticed a lot of lag between flicking a paddle and the DCT actually shifting.. I was also able to stall the engine while spinning the car out in wet parking lots.
After the update, the DCT shift lightning fast.. meaning a flick of the paddle immediately executes a shift. Also, no more stalling. BUT, as the rest of you, I now have this 2nd gear lag myself.
As detailed by many before, when slowing down for a turn, or doing a rolling stop sign, the DCT will shift down to 2nd but the clutch stays disengaged as the car thinks you might be slowing to a stop.. so essentially you are rolling at this point.. then you press the gas to go, but the clutch is not engaged so the engine management and DCT take a good 1-2 seconds to decide what to do next... if you pay close attention you will notice that the engine does not even rev up when you press the gas pedal.. the go pedal is basically doing nothing for a good 1-2 seconds which attributes to the panic feeling, especially if traffic is bearing down on you at the moment. Eventually the car realizes you want to GO, and now depending on how far you have pressed the gas pedal down while waiting, the engine will rev up and the car will either move ahead nicely or very fiercely.
I don't have my VIN handy, but it sounds like BMW is working on a fix regardless. It is March now, so lets hope we can try the next software version soon.
