Toad 4.5 had this minor bug too.
This is usually caused by a proxy on your network. It is something that we have struggled with for several versions of Toad. It turns out that there is not much that we can do because the proxy is munging the icon. Sorry for the bad news.
Heyas Dwight,ok, seems a bit strange to me, since the other icons (google, MySQL, etc) are all working perfectly.regards/Marc