I have LC (PD: 01/12/2006)from my EB2 too, and I-140 has been approved. But to my knowledge, you cannot file 140 & 485 under your EB2 at the same time, you can only use your EB3 PD date carry over according to your case.
My EB3 filed March 2003, but still didn't get LC yet. _:o