xbox 360 madcatz wiring trouble with xbox live

ok, so i'm soldering wire up to a madcatz 360 control pad to hook up with an arcade stick. i'm testing it with virtua fighter 5 and everything works fine, until i play on xbox live. on xbox live, my character won't stop blocking. as soon as the match ends, it goes back to normal. when i go back to single player, everything works fine.

does anybody have any clue why it would do this or what i can do to fix it? the back says its madcatz item number 4716 and manufactured in 2008.

ask on SRK if you haven't? Personally haven't done any soldering jobs, but there are a handful that have for stick mods.