Canon SX20 bought end 2009 and out of warranty. Since April 2011, getting intermittent lens error where on zooming, the lens goes in & out a few times then shuts down. On restart sometimes works. If not, leaving overnight & camera ok. Have tried following: 1) Resetting to Canon default settings- sometimes works 30% 2)removing batteries when switched off -still lens error 3) leaving on, removing batteries, leave for hour - fixes problem for a while. 4) Tapping case where hdmi etc are on palm of hand - seems to work for a while 5) I have replaced batteries, rechargeables & Alkalines but that does not have any impact on results. I do not wish to send it into Canon as the likely repair costs will go a long way to buying another camera
My questions to you are:
a) Could this be an electronic rather than say dust problem within mechanism

Is their a firmware update for this camera and is it user installable
c) Any other suggestions on fixing this camera