I have a pioneer dvr 105 and the latest version of nero but i get the error message "sorry this version supports Yamaha versions only" and a big red circle through the dvd writer.Any suggestions?

Sounds like you may have an OEM version of Nero, supplied with an earlier drive (Yamaha maybe).
If so, it is probable that this will only work with the drive it was supplied with.

You can easily chek this, by uninstalling the current version and downloading/installing the trial version from Nero. If this works ok, then you need a new version.

Thanks,that was exactly the problem.Uninstalled the old version and now it works.
Cheers