[XeTeX] xe(la)tex error: Fatal format file error; I'm stymied

[Martin Roppelt]

Hello,

When I run xe(la)tex with any document I get following error:

This is XeTeX, Version 3.1415926-2.2-0.9995.0 (TeX Live 2009/Arch Linux)
(Fatal format file error; I'm stymied)

I don't know what to do, what it means, or what it was caused by. I 
wonder what "I'm stymied" might mean. What can I do? Reinstall TeX?

Bye and thanks,
 Martin