iSight Problem... or not?

hello guys, does anyone know what's wrong if
isight works in skype but not in msn(version2009 running in win7 x64)?
my isight even works when i test it by using the upper right
"show menu" and then "tools > audio and video setup" on the
msn messenger dialogue window, but it still gives me a crossed
webcam icon instead of myself when making a video call.

is it related to the driver?
or is it just about how it's set up?

THANKS~>w<~