On Saturday, Microsoft and T-Mobile said that personal data stored on customers' Sidekick devices had almost certainly been lost following technical troubles with servers maintained by Microsoft's Danger subsidiary.

On Monday, the prospects of recovery had improved, with the two companies reporting significant progress and expressing optimism that much of the data could be recovered.

Early Thursday morning, Microsoft corporate VP of mobile experiences Roz Ho made it official, declaring that Microsoft had recovered "most, if not all, customer data" for the limited number of Sidekick customers affected by the outage of the past week.

Thus, it appears that not many customers will receive the $100 gift cards or data service credits promised to those who lost data.

Ho said that data will be restored as soon as possible, starting with personal contacts and followed by calendar entries, notes, tasks, photographs, and high scores.

The source of the outage, Ho said, was "a system failure that created data loss in the core database and the back-up."

Microsoft, said Ho, is working with T-Mobile to make the Sidekick service more stable and more resilient.

Nonetheless, at least two lawsuits have been filed against T-Mobile and Microsoft for negligence in handling customer data, one in California and one in Washington.

The California lawsuit, filed on Tuesday on behalf of Georgia resident Maureen Thompson, says that Thompson "suffered a complete and catastrophic loss of all data on her daugher's Sidekick," a loss characterized as "irreparable damage."

The lawsuit alleges that T-Mobile and Microsoft failed to invest sufficiently to keep promises made in marketing material about the Sidekick's "always-on Internet connection" and "automatic data back-up."

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