" Anyway, this is a kernel bug in ICS, we have to wait for new update.

" Anyway, this is a kernel bug in ICS, we have to wait for new update. The solution for this is: shutdown your Note, peel off the back cover, remove the battery; hold the battery for more than one min, put the battery back, put back the back cover; start the phone. Then, everything goes back to normal. Reboot your phone will NOT solver this issue, at least for me.
Next time, when you encounter this issue again, try the procedure again."

(cc/ Molnár-Soós Sándor István & tnx to Markó Krisztián )
http://www.allaboutgalaxynote.com/how-to-solve-battery-issues-after-ics-update-in-your-galaxy-note/