Motorola CableCARD and 6 Tuner Support

Are there only certain Motorola CableCARDs, provided by Cox, (Hardware Versions and/or Firmware Versions) that support 6 Tuners.

Someone is being told by Cox in Hampton Roads, VA that Cox Motorola CableCARDs only support 2 Tuners, and I know that is not correct. But there may be only certain Hardware Models that do support all six.

TiVo's website says: Motorola CableCARDs — version 2.65 or later, but that may be a misprint and might need to be FW* 6.25

Does anyone know the facts and Version #'s