Help cant calibrate screen after 2.1


I upgraded to 2.1 many months ago, and having been using it fine with no problems. Now recently iv found the touch calibration has been abit off, so i thought id recalibrate. Now since upgrading to 2.1, on the touch calibration screen the top left calibration target doesnt work, ie for the top left target doesnt recognise when i tap the centre red dot (it works for all the other targets), thus calibration keeps failing.

I tried re-installing 2.1, but the lg updater wont let me re-install as i already have 2.1. What can i do to fix this issue?