CSS validator bug ?

It seems to be a CSS-Level2 Validator Bug:

Message:
Unknown error
java.lang.RuntimeException: org.w3c.css.properties.css2.Css2Style cannot be cast to org.w3c.css.properties.paged.Css2Style 

URI : http://www.ub.uni-rostock.de/ub/index_xde.shtml

Please have a look to css level2-validation of our homepage:
http://jigsaw.w3.org/css-validator/validator?uri=http://www.ub.uni-rostock.de/ub/index_xde.shtml&warning=no&profile=css2

Best regards,
Joerg Simanowski
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phone/fax:  +49 (381) 498 - 86 16 / - 42
e-mail:        joerg.simanowski@uni-rostock.de
Anschrift : 
Universitaetsbibliothek Rostock, Abteilung IuK
Albert-Einstein-Str. 6, D-18051 Rostock
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