Canadian/US Tax liabilities

QUESTION:

I am a Canadian citizen who moved to the US several years
ago, accompanying a spouse who was doing post-
doctoral work at an American university.  Our visa status
was J2 and J1 respectively.  We had severed ties with
Canada and were no longer filing Canadian tax returns.   
She has recently accepted a job in the US resulting in a
change of visa status to H1b for her and H4 for me.  What
would my tax obligations be if I were to return to working
in Canada while awaiting my green card application to be
processed?  I'd appreciate any advice or assistance in
finding pertinent information.
_______________________________________ david ingram replies:
Your tax liability would be to Canada first and the US second since I would presume that your mind and heart were in the US.

You would file a Canadian T1 and then report the money on your US 1040 joint return again and either exempt it on form 2555 or claim a foreign tax credit on form 1116.

However, if you leave the US without special permission while your green card application is pending, you can NOT return to the US unless your resident alien (green) card has been issued.

To solve the problem, you must fill out form I-131 in advance to leave and re-enter the US.  the same situation applies to your spouse. �