HELP - Activa, oil temp light intermittent fault??

[cookingfat]

Hi All
Happy New Year
I changed the oil (semi-synth) on my new (to me) Activa, over filled the oil (about 400ml) the oil temp and stop lights came on when started the next day. Removed the excess, light still came on. Parked it facing up a slight incline seemed OK.
But now it will come on and off for upto 2 miles and also come on intermittently when cornering, if it is 'off' when braking or if it is 'on' go out when braking!!!? Oil level, oil temp and water temp as normal - any advice help will be greatly apreciated!!
Thanks Dave