Status update, November 18 2010: CNET was shipped a review sample of the LG 50PX950 plasma TV, the first TV with THX's 3D certification, but the review had been delayed by a bug with the TV's picture settings.
After choosing a picture model like THX or Expert and then turning the TV off then on again, or switching resolutions of the input source, the color and other picture characteristics change significantly, losing the accurate settings of the original picture mode (despite the menu indicating that the picture mode hasn't changed). The only way to restore the characteristics of the chosen mode is to switch modes manually, and then back again. The company's other TVs we've tested, such as the 50PK950, do not have this bug.
Upon being informed of the issue, LG sent us a second review sample, and it exhibited the same behavior. The company says it's working on a firmware solution, so once the solution is publicly available for users to apply to their TVs, we will proceed with the review.