Tricky Situation: Need to change job while PERM Labor is filed for second time

[bhaskomy]

Hi!
I was with company A where my Labor and I-140 were approved with a PD of March 2008. I have the copy of approved I-140 from Company A. At this stage, I was laid off and had to find a job with a small consulting company B.

Company B has started my GC and filed PERM Labor in Sep 10. My H1 is valid till March 2012 including recaptured time.

Following are my questions:
1. Can I change job now?
2. If I change job now, can the new company (Company C) start with fresh PERM again with out any adverse impact to my GC?
3. What happens if I change the job after PERM Labor from Company B is approved?
4. How can I find out if Company A has revoked my approved I-140 application?
5. I understand that if my I-140 is not revoked, I can get 3 year extension to my H1. If not I need my labor filed before March 2011 to get 1 year extensions for my H1. Please validate my understanding.

Thanks for your inputs.
Regards!

[txh1b]

1. Yes
2. Yes
3. Nothing
4. You cannot as it is the company's petition.
5. True. Once you get a 3 year extension, I beleieve, you can get the transfer done without the validity of the 140 being checked. However, consult an attorney to clarify this.