Yes, it's now travelling towards palm's assistance for warranty reparation. Let's see how's happened.
The first time, I was HotSync-ing, the handheld froze, when I reset a blinking black line was on palm's logo and nothing happened. I tried any type of reset, there was nothing to do. Replaced with DOA, as I bought it from a couple hours.
The second time I was moving a large file from SD card into main memory. Exactly the same behaviour.
From what I've read, the black blinking bar seems to mean "ROM failure". How did the ROM broke? Perhaps, the application wrote something in memory where it should not. Why this happened? Maybe for UDMH. It has been enabled two times on the handheld, and both times the palm died. Maybe it's just coincidence. Maybe not: many people use UDMH on T|E2 without problems, but anyone I heard to have this problem had UDMH enabled.
As for me, I will never use UDMH again. Moreover, it's pretty useless on T|E2 compared with other handhelds (the same program needs much morefree memory on T|E2 than other handheld: ZDoomZ, for example, should need 8MB but I couldn't play it before freeing 20 MB, of total 26 MB available. After that, the T|E2 died). Maybe UDMH is just not compatible with NVFS.