Yeep, Mine does the same thing with the gas light/gauge. My old chevy did it too, and everyone else I know with a chevy for that matter. If you ever have to replace the fuel pump thats the time to fix it. I just deal with it.
My SES light blinks due to a multiple misfire code aka the code from hell in these things. I think I mentioned that in another forum we were talking trucks. And the tow haul mode doesn't turn on...but very rarely it does..and doesn't turn off. I wish mine didn't have any rot, you should see it LOL. That must be nice.
Good luck getting to the bottom of this, I know what a pain it is havin issues with these things, trust me. Atleast you don't drive a ford