Valid Page fails validation?

Greetings,

I guess I'm the first person ever to claim this, but either I don't know 
(X)HTML or

http://www.math.tu-dresden.de/~kuettler/programs.html

fails validation for no reason, i.e.: wrongly.

http://validator.w3.org/check?uri=http%3A%2F%2Fwww.math.tu-dresden.de%2F%257Ekuettler%2Fprograms.html

says ``Failed validation, 1 Error'' and

Validation Output:  1 Error 
Error Line 31, Column 0: 37 +0200 (Wed, 01 Aug 2007) $.

It seems to have problems with the · entity reference, but to the best 
of my knowledge there's nothing wrong with this page (HTML-wise).

Regards,
Heinrich Küttler

Received on Thursday, 2 August 2007 11:04:28 UTC