[XeTeX] Is this a XeTeX issue?

[Alastair M. Paterson]

Hi!

I'm trying to typeset some Tibetan text on Windows  XP using MikTeX.

The resulting PDF is not rendering correctly when loaded into Adobe 
Reader 8.
I have an up-to-date version of usp10.dll (uniscribe) which renders the 
text.

If I copy and paste the text from Adobe Reader into OpenOffice, it then 
renders correctly.
I can use CutePDF to create a new PDF file which when reloaded into 
Adobe Reader now appears correct!

Not sure if this is anything to do with the XeTeX output or is a 
completely unrelated issue.

Thanks

Alastair