[mastercare]

hi all this may be simple question to those in the know...
i have purchased gears of war for pc and have a gold account with xbox live...

my son has gears of war for his xbox360 and a silver account i think...
he wants to play me cross platforms that is via xbox live pc -V- xbox360
if he invites me to a game i see his invite to play fine..but my end on pc thats as far as i get it says restart to game and accept invite this does not work...
the xbox is on a lan along with other pc/s in the house...
or am i asking the impossible...
cheers in advance for your replys
mastercare