Hi Fantail, no, I do not use Comodo. Thanks for the Subsim thread - every little helps

Also for the tips on installing. For me it doesn't matter too much that I can only play in vanilla as I have the GWX version on my old XP machine, so I get to play both, the machines being linked by KVM - but other folk might find the solution there.
Tarjak, sorry my solution did not work for you, disappointing. You say you think it is a refresh issue or the way Windows 7 handles 3D - and that may be so; I am not saying it is not - but I have noticed, while looking for my own solutions, that what works for one person does not work for another. That was true for me, and now we see it is true for you, so that makes me think that the problem lies in the individual machine configurations rather than a 'global' problem due to the operating system....