i just added two routes into my core router of
ip route 66.151.158.177 255.255.255.255 Null0
ip route 216.115.217.45 255.255.255.255 Null0
This kills the constant polls that gotomypc uses in order to come back through your firewall.
If you want to find out who is using it you can build an access list around those two.
Access-list 101 deny ip any host 66.151.158.177 log
access-list 101 deny ip any host 216.115.217.45 log
acess-list 101 permit ip any any
Check your log files and it will tell you the internal IP addresses that tried to access those sites.