I installed StabilityTest 2.7 through the Market app. Tried with power-off/power-on, no Wi-Fi mode. The test (Classic Stability Test) failed after 1 minute and 13 seconds (5 successful runs with RAM, 0 with CPU). App froze, Home button worked, Settings|Shutdown worked... Tried for the second time ( 22 sec, 1 RAM, 0 CPU)
Can somebody try the StabilityTest on working device, please? If it works fine this could indicate we are dealing with the HW issues and devices need to be replaced...