Android : Why some UI elements dissapears when activity is relaunched?

Sometimes, when the android activity remains a long time in the background and it is relaunched (using "FLAG_ACTIVITY_REORDER_TO_FRONT" flag ) to foreground again some UI elements (images and texts) are missing.

Original activity:

Relaunched activity:

This error rarely occurs and I can't find the solution. I suspect it may be caused by the android system which removes the UI elements by low RAM but I not find any solution looking for the log output.

The system log only show this unexpected traces (any error):

    09-17 13:59:44.259: W/CpuWake(432): >>nativeAcquireCpuPerfWakeLock()
    09-17 13:59:44.259: W/CpuWake(432): <<nativeAcquireCpuPerfWakeLock()

The activity has a high memory/graphic consumption and the application has enabled the "largeHeap" flag into the manifest.

I haven't found valid information searching about the "nativeAcquireCpuPerfWakeLock" warning.

I would be happy about some help.