i submitted I751 3 days ago and we moved to a new home we live in FL of course we sent our case to Vermont Center instead of Texas,now i wanna send I-865 sponsor address change and on the instruction it says if you live in FL send the application to Texas Service center i was thinking since we sent I751 to Vermont we also have to send I 865 to vermont too right?? help me please thanks a lot .

I would send the I-865 to the address specified in the I-865's directions.

I would also call USCIS and make sure that the I-751 case is updated with new address, no sence in any correspondence and perhaps green-card getting lost.

Post office wont forward anything sent to you by USCIS, letters tend to have "Return Service Requested" on them.

You can change your address online, which consists of submitting an AR-11 electronicaly. It will ask if you have any cases pending, and will get the additional information.

https://egov.uscis.gov/crisgwi/go?action=coa

As for the I-865, as YuAndDan already suggested, follow the directions and send to TSC.