One is that the DDMS do not find the emulator, and there is no log when the Android is starting up, which also means that you do not see anything and cannot debug your app.
There are some ways of fixing this.. all need a console (cmd) to type in.
Try using the “Reset adb” option from the DDMS Devices view menu, or restarting the server at the command line:
[sourcecode language=”csharp”]adb kill-server
adb start-server [/sourcecode]
If that does not work, then try this instead:
Start Emulator, wait for it to come up, then type the following
[sourcecode language=”bash”]adb kill-server
adb logcat -c[/sourcecode]
If lucky, the logcat command promt will restart the process and you will find the log to start in both eclise and command-promt. This will also give DDMS the right push to find the emulator and it is now possible to debug it in Eclipse.