Interesting...
I got this battery drain problem shortly after my tablet had been returned from repair because the keyboard dock battery was draining when the dock was disconnected, I RMA'd it for repair on 17th December (no-one at ASUS mentioned software...).
I got the tablet back on 22nd January, after a couple of complaints about how long it had been, and had exactly the same problem as before. According to the paperwork they had 'REPLACED MAINBOARD, LCD ASSEMBLY, I/O FPC AND MIC RUBBER, RECOVERED OPERATING SYSTEM, END TEST PASSED.'
The Kernel version was 3.4.66-g96e53b8 and the Build number KOT49H.WW_epad-11.4.1.17-20140711.
When I found this thread today I downloaded the kernel update (couldn't get it OTA), so I'm now on 3.4.66-ge79544a, KOT49H.WW_epad-11.4.1.29-20141218.
1. I'll be interested to see if this cures the problem
2. I'll be interested to hear what ASUS have to say, I demanded a refund when I found out that they hadn't fixed the problem.....