Apple released an update to the Thunderbolt firmware that should address problems users have experienced trying to get bus-powered peripheral devices to work.
Today, Apple made available a Thunderbolt firmware v. 1.1 update that addresses " an issue with MacBook Pro (mid 2012) and some Thunderbolt cables that may prevent bus-powered Thunderbolt devices from functioning properly." Apple first introduced the Thunderbolt technology with its MacBook Pro line in early 2011. Thunderbolt I/O allows high-bandwidth communication between devices -- up to 20 times faster than USB 2.0 and up to 12 times faster than FireWire 800, according to Apple.
The update requires OS X 10.7.4, but Apple's Software Update should determine whether your system requires it. You can also go directly to the support site and download the 442KB update here.
What kind of problems, if any, have you encountered with the Thunderbolt technology? Let us know if the firmware update solves any of your issues.