xiaobaitu, please help

I485 was approved after interview one year ago, but due to regress of visa bulletin, I was not given green card at that time. Visa numbers became available since this Jun, many cases like mine have been approved. I called USCIS twice, infopass twice, only received a 2nd fingerprint notice.
I have to quit my job for some reason, is it safe to do now?
my information:
NIW, I140/I485: 9/21/05, I140 approved on 9/27/05, interviewed by TSC 8/06
1st fingerprint: 11/05
2nd fingerprint: 7/07
thanks a lot