Walsh's update tool is still available on mirror sites, according to comments on his blog. He did not immediately respond to a query about why the tool is no longer available on his site.

Via Twitter, Walsh is defending the tool, saying that the few problems that people have had are a result of failing to follow download instructions. "Eric stipulated they don't know what it'll do as they haven't tested it. But I've tested it :-)," .

Microsoft started pushing out the very first update, designed to smooth the update process, in February. That software made some Samsung phones unusable. A follow-up software refresh, which included cut-and-paste capability and other performance enhancements, was delayed so that the company could try to improve the process.

Neither update has reached three of five phones eligible for updates in the U.S., according to a on the official update process. Those phones are still in the testing phase for both software updates. The site says that phase should be complete in early April. After that comes a scheduling process that can take 10 days, followed by batched delivery.

Walsh and two other developers became known in the WP7 community when they released a tool that would let users upload applications that weren't approved in the Marketplace. But Microsoft approached the trio, promising to do more to let developers test applications on their phones and warning that its update would close the hole that allowed the unlocking tool to work.