OpenType fonts can contain Type 1 data, TrueType data, or both for cross-platform compatibility. The fonts supplied with Win 2K seem to have both, which is why Xara is seeing double. The Type 1 data is a duplicate of the TrueType data and is only included to accord with Microsoft's Open Type initiative. Unless you have some apps. dependent on Type 1 fonts, the temporary solution appears to be to uninstall the new OpenType fonts and replace them with the ordinary TrueType versions.

Regards - Sean