7th yr H1 X-fer/Ext thru Company-B while i-485 pending.

[rahuljee]

I have i-140 approved and i-485 pending and have EAD too. But I'm still on H1 since I haven't been able to file my wife's i-485(visa numbers unavailable and she's on H4). My 6yr term completing in March '06 and I know I can extend my H1 with the current employer for 3 more yrs. I have a good offer from another company, so my question is can I transfer/extend my H1 through the new company and file AC21? Will it affect my GC approval in any way if I do ?
I was told it would invalidate my whole GC process, is that true?

Thank you,
Rahul.