It appears that a large amount of SonyEricsson T608s may be defective. Running the Real Time Clock service test (Dial ##786 > Menu Key > Add Number > Menu Softkey > Service Screen > Service Tests > Real Time Clock) shows that the T608 fails… a lot. Multiple T608s tested have shown the test to fail from anywhere between 10% to 66% of the time.
What makes this even more distressing is that no other working SonyEricsson phone that has this test fails it… ever. If you have a T608, run this test 10 times and post your results. If anything, showing a built-in diagnostic fail to a Sprint Store tech is an easy way to get your T608 replaced.
The Real Time Clock test is designed to test the ability of the phone to keep track of time itself. This is especially crucial on CDMA networks, as the phone needs to stay in sync with network time in order to function properly.