netmeg - 4:53 am on May 3, 2007 (gmt 0)

When issues like this occur, they typically occur for a very small percentage of all advertisers. In light of this an 'alert' message in all accounts (including those of the majority who are not experiencing the issue) might prove to be unnecessarily alarming - and not taken kindly.

I think this situation could be ameliorated by some careful wording - all you'd have to say is "Some users may be experiencing difficulties with thus-and-so - please be aware our engineers are aware and working on the issue. We appreciate your patience while we work to resolve this issue as soon as possible"

Just a simple statement like that could possibly save HOURS of otherwise wasted time.