So how can I fix this problem. It seems my DDMS is broken down.
                
                A: 
                
                
              Is it a real device, or the emulator?
If you're getting that from a phone, logging might be disabled. try this in adb shell:
echo 1 > /sys/kernel/logger/log_main/enable
echo 2 > /sys/kernel/logger/log_main/priority
But, if you're getting that after a while (some logs get printed, then it stops), try:
adb logcat -c
                  racetrack
                   2010-09-29 17:08:09
                
              I just tried the logcat and it is working now.
                  Chun
                   2010-09-29 17:15:14
                I am just wondering what causes this problem.
                  Chun
                   2010-09-29 17:15:56
                Most likely an android bug.
                  racetrack
                   2010-09-29 20:28:54