java.io.IOException: Unable to open sync connection! in to the Nexus

I try my application run on eclipse but i found these errors. which is faced first time so would you please give me any ideas for these error. i am currently using Nexus mobile. if you want see original question please click this link.

  [2011-08-04 15:59:09 - SightWords] Android Launch!
  [2011-08-04 15:59:09 - SightWords] adb is running normally.
  [2011-08-04 15:59:09 - SightWords] Performing  com.horror. android.SightWorldsActivity

                                     activity launch
  [2011-08-04 15:59:09 - SightWords] Automatic Target Mode: using device 'HT9CRP800333'

  [2011-08-04 15:59:09 - SightWords] Uploading SightWords.apk onto  device 'HT9CRP800333'

  [2011-08-04 15:59:09 - SightWords] Failed to install SightWords.apk on device 'HT9CRP800333': 

                                     Unable to open sync connection!
  [2011-08-04 15:59:09 - SightWords] java.io.IOException: Unable to open sync connection!

  [2011-08-04 15:59:09 - SightWords] Launch canceled!

 Answer

1. No it is not about your code. Try to plug usb out and than plag it in again. If it is not help try to reboot you device. Usually it works for me in such cases.
2. I had the same problem, even if with my emulator.
   Occasionally, the Device view in the Eclipse DDMS would list many copies of the device, all of them Offline, and I wouldn't be able to run anything on the device if I tried to plug it back in.
   
   What seems to fix this is running
   
   adb kill-server
   
   from the command line. It cleans up the list of Offline devices and allows me to run applications on the device again.
   
   Hope it works,
3. Phone connected to the computer's USB port. Sometimes disconnecting and reconnecting the cord worked but then it stopped working completely. However, disabling USB debugging on the phone and then re-enabling it has worked so far. Hopefully it keeps working! These fixes really seem like silly hacks.. I'm not sure what the underlying problem is.
4. I was able to clear this only by cycling the USB Debugging option on the phone.                                                  Settings -> Applications -> Development -> USB debugging