I too have had this problem from day 1 of the engine having been swapped for a freshly rebuilt one... will have to get it investigated but it seems purely electrical because for example... they'll come on and off randomly, but sometimes they'll come on when i turn on other electrical things, like the rear windscreen demister... and quite often when i'm indicating it'll come on each time the indicator flashes, so it flashes in sync with the indicators!
Is there anything to check before going to have my pants down by a garage?