Weird CSS warning...

When I check my site with the CSS validator I get a really strange
warning: Regel
: 23 (Level : 1) U heeft geen kleur voor uw achtergrondkleur opgegeven :
#autoXML14684481468448
But there's no #autoXML14684481468448 in my site at all...
My validation is:
http://jigsaw.w3.org/css-validator/validator?uri=http://epsilon.uwhosting..net/~mauz/
I'm hoping you could tell me what this is all about..

Thank you in advance,
Maurice Robert (NL)