Im having the exact same problem… ever since the current 2.62 upgrade – my tag cloud has not updated with any new or more popular tags. HELP!
Is it a Yahoo thing? i noticed that i get the same error when i subscribe to the RSS feed for this topic, and when i try and subscribe to a completely unrelated xml feed from another one of my sites. It wont work if i try and run it through feedburner either. Strange that i can add blogger.com rss feeds to my yahoo just fine though.