Microsoft may owe T-Mobile millions of dollars for its just-concluding Sidekick outage, an inside tip may have revealed today. Like most carriers, T-Mobile is believed to have a service level agreement (SLA) with Microsoft and Danger to guarantee uptime but may have a particularly costly deal with Microsoft. The MobileCrunch source claims that Microsoft will likely pay a rate roughly equal to $700,000 per day for the period it couldn't guarantee 99.5 percent availability of Sidekick services.

As the last failure invoking the fee was in 2005, when Danger was still independent and had fewer subscribers, the actual penalty is likely to be higher, the contact says. If real, the SLA would lead to Microsoft owing $9.8 million or more given the approximately two-week absence of Sidekick data.

None of the involved parties have commented on the accuracy of the rumor, but the sum would further compound damage to Microsoft's reputation following multiple lawsuits that have already been filed this week. These and critics have also accused both Danger and Microsoft of depending almost exclusively on online-based storage to keep users' Sidekick information and for not having a known working backup on-hand.