It appears that the Ingeniux application build that we installed in early December (the version with support for IE 7) is much less tolerant of multiple attributes with the same name. The system error is very specific:
REASON: No attribute name may appear more than once in the same start tag or empty element tag.
In this instance, as in another case in late December, the offending attribute name is “NewWindow.” Since this attribute is used in a global export, I have, on the advice of Jason at Ingeniux, commented out lines 1178 and 1434 of CustomUtilities.inc, which should resolve this problem.
If this error recurs we’ll have to look for a different export and fix that one as well.