error in SAX2XMLReader.t

Anybody any idea what goes wrong here?

prove -v t/SAX2XMLReader.t

not ok 17 - setProperty(): fgXercesSchemaExternalSchemaLocation

#     Failed test (t/SAX2XMLReader.t at line 239)
# Here's the error: Value is read-only. at t/SAX2XMLReader.t line 237.
not ok 18 - setProperty(): fgXercesSchemaExternalNoNameSpaceSchemaLocation

#     Failed test (t/SAX2XMLReader.t at line 246)
# Here's the error: Value is read-only. at t/SAX2XMLReader.t line 244.
not ok 19 - setProperty(): fgXercesScannerName

#     Failed test (t/SAX2XMLReader.t at line 253)
# Here's the error: Value is read-only. at t/SAX2XMLReader.t line 251.
ok 20 - setProperty(): fgXercesSecurityManager - throws exception
not ok 21 - The object isa XML::Xerces::SAXNotSupportedException

-- 
Marc Lambrichs
====================================