when Microsoft blamed mobile carriers for the delay, a problem that Patrick Kerley, who also works at Levick, said .

Earlier this week, Microsoft again said carrier testing for Windows Phone 7 smartphones made by HTC, LG and Samsung was not finished, prompting owners to again blast the company in more than 120 comments appended to a blog post.

The update snafu has prompted customers to call Microsoft confused and incompetent, especially after an independent developer figured out a way to grab Windows Phone 7 updates directly from Microsoft's servers. Microsoft later pressured the developer to , saying "It's even possible your phone might stop working properly."

On Wednesday Belfiore blamed the delays on a wide range of problems, including glitches in early versions of some handsets, a pause to verify that its update mechanism was working properly, and carrier testing of the updates. He also admitted that coordination between Microsoft, carriers and smartphone makers had not been up to snuff.

"One thing we struggled with is each of these things involves us and the OEMs or handset manufacturers and the mobile operators, and it's hard to coordinate which things we can say about what other people are doing," Belfiore said.