Fuel gauge problem solved?

I actually managed to pump slightly more than 11 gallons (with no top off) last week with 499 miles on the tank. That's the most I've ever put in the tank and I was a bit nervous about making it to the gas station -- my wife had run more errands than expected while I was at work and when she picked me up I couldn't believe she hadn't tanked up!

I don't know if there's a difference in the bladder or perhaps it's a matter of conditioning. After my first couple of fillups when the car was new I took the advise of someone on this board and drove the car for 10 x the tank mpg before looking for gas while ignoring the blinking bar on the gauge. Is it coincidence or did doing that a couple of times "fix" it?

Now..if I could just improve that mpg! Now that the Summer season is near I should have a chance to be the solo driver of the Prius for a week or two and I'll find out if I can break that magic 50 mpg mark for an entire tank. Up 'till now my wife has had the car during the day about 2 days a week and that always seems to bring down the mpg a little.