can MTR be filed while outside the country if i485 is denied?

[coolpal]

My i485 (EB2I) with PD of Dec-2006 is still pending and I have valid AP till Mar 2012. There is a need for me to travel out of the country in November/Dec 2011, and if my i485 is not approved by then, and if I decide to travel using AP, and god forbid, USCIS denies my i485 for wrong reasons, can I file for MTR while I am outside the coutnry and return on AP once MTR is accepted?

This is a hypothetical question, but of utmost importance to me to consider my options for travel. Any help is greatly appreciated.

Thanks in advance.
pal :)