i can't believe some people have such silly problems. so why do you want to keep your canadian green card now anyway? do you think Aliens will come in their spaceship and take over usa and you need to have canadian green card entact or something? why don't you get over with the sillypropblems and enjoy your life now you have a green card and a decent job... you've wasted half of your life already worrying to about these things..now enjoy man.. forget about canadian gc... once you've a us citizen you can always go to canada anyway...

oh ya, btw, a friend of mine filed for a " no entry" permit and was able to leave for 2 years maintaining his green card status.. if tat helps you