IMSDroid can't receive incoming event after turn off screen 10-15 seconds - Android 4.3

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What steps will reproduce the problem?
1. Install and Log in to IMSDroid
2. Turn screen off for 10-15 seconds
3. Using another device call to IMSDroid

What is the expected output? What do you see instead?
- Expected: ISMDroid should ring and turn on screen with phone number of caller
- Real result: IMSDroid show nothing, no ringing or turn on screen. Nothing has
been showed in DDMS

What version of the product are you using? On what operating system?
- Version: Latest v2.x
- OS: Android 4.3

Please provide any additional information below.
If i keep my screen turn on, everything worked as expected. This issue only happens if screen turn off for 10-15 seconds. After that, even i turn on screen still cannot receive call from others but out call still works. I also check the service isStarted and isRegistered, they returned true.

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Original issue reported on code.google.com by `trungken...@gmail.com` on 1 Nov 2013 at 2:38