then a little dialog box pops up telling me 'Sorry Flanger requires Cubase5' which I have.

I asked about this on the VST mailing list and steinberg tech support replied - it turns out that those plugins that say "...requires Cubase 5" are NOT VST plugins at all. They are simply Cubase extensions.

They use the VST interface but then they start making manufacturer specific calls (VST uses a call back method and opcodes). Try as I might I couldn't reverse engineer what was going on in a sensible fashion.

Annoying really 'cos some of these "Extensions" do some useful things.

cheers

mark