Same here. Wake locks setups aren't helping much. So there is something going on in the background. Bad very bad!
You can press the "Thanks" button if i have helped you in any way
Previous Phones - Sony Ericsson W705 > Xperia X10 Mini Pro > Xperia Ray ST18i
Now - Xperia ZR C5502
Stock 4.3 Until the next proper Kitkat update
For now I'm loving it