http://doc.trolltech.com/4.7/qscriptvalueiterator.html#remove

This is a "convenience" for setProperty(it.name(), QScriptValue()) (i.e., deleting the property).
remove() is not guaranteed to delete the property, though, since the property might be undeletable, and there's no way of telling since remove() returns void.
We suggest that remove() is removed, so that standard ("non-magic") property deletion must be used instead.