So far I've measured just over 11A when both the Heated bed and the Hotend are both active.

MAKE SURE YOU ARE AT EXACTLY 12V, i had my Power Supply set at 12.1V and continuously had random disconnects when heating or cooling the heated bed, must have been over voltage protection doing its job :)

I've also added {M140 S0 ;} to the end G code section under "Printer Settings" in Slic3r.

this disables the heated bed after the print finishes.

**UPDATE: I think I've found the answer, http://help.printrbot.com/Answers/View/5242/Brown+out+reset:+Printrboard+or+PSU

Bill had a similar problem "Bad heated bed. The bed was sporadically pulling enough current to trip the PSU short-circuit protection. I replaced it with a RepRap MK2B heatbed dual power from Amazon and after 20+ hours of trouble-free printing it is clear that that was the problem."

It may be that the fancy Kapton Nichrome heater is causing a similar problem on my board.

At the moment the reset problem seems to be contained to the heat up process and just after a print. luckily whenever I get the print stared it runs through and only resets and hangs up after finishing so I'm OK with it for now until I find a solution, It also works much better since I added the indicator LED.