Crash on returning to foreground

[ffolkes]

I've had this crash now and then for weeks, I never got a chance to pull a log until now. When Synapse is used, left alone, then returned to after some time, it immediately crashes with:

W/dalvikvm(27609): threadid=12: thread exiting with uncaught exception (group=0x414e1ba8) E/AndroidRuntime(27609): FATAL EXCEPTION: pool-1-thread-1 E/AndroidRuntime(27609): Process: com.af.synapse, PID: 27609 E/AndroidRuntime(27609): android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views. E/AndroidRuntime(27609): at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:6094) E/AndroidRuntime(27609): at android.view.ViewRootImpl.invalidateChildInParent(ViewRootImpl.java:857) E/AndroidRuntime(27609): at android.view.ViewGroup.invalidateChild(ViewGroup.java:4320) E/AndroidRuntime(27609): at android.view.View.invalidate(View.java:10942) E/AndroidRuntime(27609): at android.view.View.setBackgroundDrawable(View.java:15434) E/AndroidRuntime(27609): at android.view.View.setBackground(View.java:15329) E/AndroidRuntime(27609): at android.view.View.setBackgroundColor(View.java:15291) E/AndroidRuntime(27609): at com.af.synapse.elements.SCheckBox.valueCheck(SCheckBox.java:138) E/AndroidRuntime(27609): at com.af.synapse.elements.SCheckBox.access$000(SCheckBox.java:31) E/AndroidRuntime(27609): at com.af.synapse.elements.SCheckBox$1.run(SCheckBox.java:79) E/AndroidRuntime(27609): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) E/AndroidRuntime(27609): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) E/AndroidRuntime(27609): at java.lang.Thread.run(Thread.java:841) W/ActivityManager( 3611): Force finishing activity com.af.synapse/.MainActivity