[XeTeX] 00F5 low line - problems?

[Daniel Stender]

Hi guys,

I've got problems with a 005F (LOW LINE) "_", the xelatex run stops with:

! Missing $ inserted.
<inserted text> 
                $
l.28 ... ihrer Klasse auf. Vorläufige Regeln: n/_
                                                  velar > ṅ
?

What's happening?

Greetings,
Daniel Stender