Here's one that fails:
you'll have to click on the Test link as NetSurf doesn't do frames.
also, this one doesn't work properly (though it used to...):
according to the spec, colspan=0 should span all columns from the
current column to the last column in the current column group and
rowspan=0 should span all rows from the current row to the last row in
this table section. (HTML401 11.2.6)