Graphicool: not very helpful, I know, but I just installed AllShare on an XP machine and a W7 machine, and didn't suffer that problem. My problem was getting the TV to see the PCs. For reasons I don't understand, it can now see the W7 machine, but not the XP machine.
Out of interest, which TV did you get? I got the UE40ES8000, and I couldn't be more thrilled with it.