same exact error on WP 3.3.2 and 3.4. The error occurred in the last few days only. Prior to June 18, 2012, there was no errors for ask.com submissions.
It is not so much the fact that Ask.com is a small search engine as the issue of errors occurring in WordPress and SiteMap execution.
Usually… one error will set off other errors and then we have one big mess on our hands.