First, I verified that the RSS 0.91 spec is more honored in the breach than the observance. Then I switched exclusively to Atom 1.0.
Time to destroy the internets again. But only for those Aggregators with an 'X" in column four in this table. Non-IE based aggregators with an X in this column will simply see silent data loss. IE-based aggregators with an X in this column that aren’t based on white-listing may see a repeat of last Tuesday.
If your aggregator is broken, point the authors to section 3.1.1 of RFC 4287.