I wrote a story in today's paper about Microsoft's advertising system, adCenter, and some of the ups and downs it has gone through in its first year. You'll likely hear more about Microsoft's advertising plans tomorrow when Bill Gates speaks at the company's annual Strategic Account Summit.

I talked to quite a few Internet marketers about adCenter, and found that across the board they praised adCenter's return on investment, but complained about the low traffic coming in to Microsoft's search engine. The story also mentioned some of the technical issues that adCenter has had, including some problems with usability and speed.

Someone who has worked on the adCenter application for the last two years wrote me to say that Google and Yahoo! have had similar technical problems as well.

My story was about adCenter specifically, and not what's happening with the competition. But in the interest of fairness, here and here are some examples of glitches with Google adWords.

Some advertisers had a messy time converting to Yahoo!'s new Panama advertising system. You can read more about those glitches here.