Hi i cross flashed my S500i to W580i, then applied display_tpa_in_java, SP unlock, Faster File Name Scrolling, MP4 recording format, advance range of brightness, remove setupwizard, hyperbass and remove fitness vkp patches. Then i deleted camera shutter sounds and applied the Everchanging theme. As well as changed the brightness to 10%.

Now When ever i press a button on my phone the number keys light up for a split second, its not really debilitating but it does waste batteries and probably does wear out the lights a bit from the flashing...

Anyone hear of this problem before? or how to fix it?

Well you have done a way lot to save yyour batterie life - mean like batteries are already been made to work ona certain age limit - we cannot save it from being worn out one day, but good to read that you have sacrificed your demands for batteries.
Now about teh flashing light thing , it is as per as light age is concerned , is bad for those lights,sudden flasheds of light is bad as it way burn the diodes of the light.
You may do somehtingg like disable the light peemenantly or connect the lights to a seperate jack with the batteries.

ITs probably something to do with your 10% brightness... Stay around the 60-100% region.

okay yea i switched it to 30 % and its not quirky anymore thanks guys

No problem.