thanks for that...
TCDWidgetSet.DoOpenURLWidgetsetImplementation just splits the URL in to the "protocol" section and the rest and then passes those strings on to Lava (by the looks of things). When I run it in the emulator it seems to turn that straight in to a google search query, rather than opening the actual URL. So I don't know where the problem is and I don't think I can work it out so I'll just never put a clickable link into an Android app if I ever write a proper one.