avd运行时报nullPointException

[2012-12-01 15:48:42 - ddms] null
java.lang.NullPointerException
at com.android.ide.eclipse.adt.internal.launch.DeviceChooserDialog.exec(DeviceChooserDialog.java:701)
at com.android.ide.eclipse.adt.internal.launch.DeviceChooserDialog.deviceConnected(DeviceChooserDialog.java:585)
at com.android.ddmlib.AndroidDebugBridge.deviceConnected(AndroidDebugBridge.java:785)
at com.android.ddmlib.DeviceMonitor.updateDevices(DeviceMonitor.java:405)
at com.android.ddmlib.DeviceMonitor.processIncomingDeviceData(DeviceMonitor.java:325)
at com.android.ddmlib.DeviceMonitor.deviceMonitorLoop(DeviceMonitor.java:193)
at com.android.ddmlib.DeviceMonitor.access$000(DeviceMonitor.java:44)
at com.android.ddmlib.DeviceMonitor$1.run(DeviceMonitor.java:84)