In an apparent response to user complaints, Apple today released a firmware upgrade that it said fixes an issue with the drive interface in new MacBook Pro.

Apple said the MacBook Pro EFI Firmware Update 1.7 fixes a problem reported by "a small number of customers" using drives based on the latest SATA specification with the new MacBook Pro line, released this month.

But Apple warned that it has not shipped drives operating at the higher-speed specification, saying, "While this update allows drives to use transfer rates greater than 1.5Gbps, Apple has not qualified or offered these drives for Mac notebooks and their use is unsupported."

Apple apparently downgraded the serial ATA interface on its most recent MacBook Pro laptop models, moving from a 3Gbps interface to 1.5Gbps.

Most industry observers spoken to by our sister site Computerworld speculated that the MacBook Pro line was experiencing higher than acceptable data error rates related to the 3Gbps SATA interface.

Apple has yet to respond to multiple requests for information about the reason for its SATA downgrade on the MacBook Pro.