AND have you contacted Icetv ? Can not see anything listed on their support forum at
http://www.icetv.com.au/iceforum/
It always amazes me why so many posts about icetv configuration or issues end up here, without going to the actual company.
I guess your right about the registry... its a 32 bit application and 64bit Vista does not update the registry as expected of it... There is part of a thread over at the icetv forums discussing it, with solution provided, and a couple of responses saying it fixed it...
http://www.icetv.com.au/iceforum/index.php?topic=346.0 maybe helpts?