Basically, Tepco admits to the fact that it's hard to be confident with some of the data, but marginal data is always better than no data
More on the unit 3 reactor
The WSJ online reports that "substantial damage to the fuel cores at two additional reactors of Japan's Fukushima Daiichi nuclear complex has taken place", "further complicating the already daunting task of bringing them to a safe shutdown while avoiding the release of high levels of radioactivity".
It also mentions that "the pressure vessel a cylindrical steel container that holds nuclear fuel, "is likely to be damaged and leaking water at units Nos. 2 and 3", and that "there could be far less cooling water in the pressure vessels of Nos. 2 and 3, indicating there are holes at the bottom of these vessels, with thousands of tons of water pumped into these reactors mostly leaking out".
Units 1,2 and 3 may all be in the same boat.