NTFS 1.5TB USB HD Not Seen

I can see a NTFS 500GB HD (LaCie), I can see a 500 Gb Free Agent HD (NTFS), but I cannot see the 1.5Gb HD (Seagate Free Agent), while connected to the USB of my Apple TV.
I see the HD as a Volume, but I do not see the files.
I take the drive and put it on a Mac or PC, and I can see all files, but not on the Apple TV (all patched with latest everything as specified in these forums).
Has something changed?
Do I need to do something else?
Thanking anyone who may offer any help well in advance, as it appears not much support, just a lot of complaints about woes.

January 17, 2009 (Computerworld) Seagate Technologies’ online support forum has been riddled this week with complaints from owners of the high-capacity Barracuda 7200.11 hard drive, which in recent months had already drawn some complaints that the drive has been freezing up during data transfers or failing all together.

The Barracuda 7200.11 is the eleventh generation of Seagate’s flagship drive for desktop PCs and comes in capacities ranging from 160GB to 1.5TB. Complaints have not been limited to Seagate’s online support site. They have also rained in on other forums. The complaints involve drives running Linux, Mac OS X and Windows Vista.

The company said in a statement Friday that indeed a problem has caused some drives to fail and it said it isolated the issue to a firmware bug affecting not only the 7200.11 but several other models manufactured through December 2008. Those include the DiamondMax 22, the Barracuda ES.2 SATA and the SV35.

Seagate is offering a firmware upgrade that it says will fix the issue.

“In some circumstances, the data on the hard drives may become inaccessible to the user when the host system is powered on,” the statement said. “If you have one of the affected products … we recommend that you update the firmware on the disk drive.”

According to users, the drives tend to freeze for about 30 seconds during I/O transfers of streaming video or when reading or writing files at low speeds. One law firm, Kabatek, Brown and Kellner LLP, even states on its Website that it is considering a class-action lawsuit against Seagate because of the number of complaints about the Barracuda 7100.11.

Seagate said users should visit its support Web site to determine if their model drive is affected by the bug.

Seagate also offers support by telephone: 1-800-SEAGATE (1 800 732-4283).

Seagate did not offer a link to the firmware upgrade, saying only that "customers can expedite assistance by sending an e-mail to Seagate. The e-mail should include the disk drive model number, serial number and current firmware revision.

“We will respond, promptly, to your e-mail request with appropriate instructions. There is no data loss associated with this issue, and the data still resides on the drive. But if you are unable to access your data due to this issue, Seagate will provide free data recovery services,” the company said. “Seagate will work with you to expedite a remedy to minimize any disruption to you or your business.”

Seagate released the four-platter drive, Barracuda, it’s largest drive ever, in July. Seagate attributes the drive’s extraordinary density to perpendicular magnetic recording technology, which stands bits upright instead of laying them flat on the surface of a platter, thereby taking up less space per bit.

Computerworld had no issues with the drive when it reviewed the hardware in October, but some reader comments indicated at the time there were issues with drives failing.