Mike,
Sorry for the late reply, I only just had chance to try your suggestion.
Low and behold it worked! Except I didn’t quite re-install Vegas 9. I ran the Vegas 9 installer, which recognized I needed a Windows .NET framework update, it located, DL’d and installed. Instead of proceeding and installing Vegas I quit the installer, opened Vegas 10 and the effects are now fully functional again!
Many thanks for your support, I hope this information will help you in assisting people in the future.
Bren