When mine gets down to one or two bars, sometimes when I start it, the gauge will flash, then after a mile or two, it's back up to one or two bars. Never had it happen on a full tank though. To be honest, I don't use the fuel gauge, I set the trip every time I get gas, and know that I get about 200 miles before it starts flashing, or 250 miles until I'm empty. I just always fill up around the 200 mile mark. I'm old school, and motorcycles didn't always have fuel gauges.
Edit...just noticed this was in the 300 forum, so my mileages may be different than what the 300 gets.
I don't care what you ride, just ride.