For people that still experience the freezing problems with their 1.5TB Seagate Barracuda 7200.11 hard drives, here is some relief for you. As previously reported here, Seagate has released a new firmware for the small number of drives with strange behaviour. Here's the official statement:

Some Seagate Barracuda 7200.11 1.5TB hard drives may show uncharacteristic operation when used with Mac and Linux operating systems in multi-drive configurations. Users may experiences pauses in video streaming applications or a dropped drive from RAID arrays. Customers seeing these symptoms should contact Seagate Technical Support for a firmware upgrade. In order to assure the proper application of the new firmware, please email a description of the issues you're seeing to Seagate (discsupport@seagate.com) Please include the following disk drive information: model number, serial number and current firmware revision. Also, please describe your system, operating system and the application in use when the issue arose, and you will receive a prompt response with appropriate instructions. As an alternative to the contact email address above please access http://www.seagate.com/www/en-us/about/contact_us/.

Again, to obtain the firmware first you need to find your HDD's model number, serial number, current firmware version using either Seatools for DOS or just look at the drive's sticker it should be written there, and finally you need to describe your system specs, operating system and the application in use when the disk freezes. After you have that information, please contact Seagate Technical Support, by email or by phone, they'll send you the new firmware and probably tell you how to update.