mileage didn't reset after gas fillup

Hi all, I have never had this happen, but when I filled up with gas today the mileage in the display didn't reset to back to zero after I turned the car back on and drove away. Is this indicative of a problem, or is it just a fluke? Has anybody else ever experienced this?

 

This is a 2008 Prius, the mileage for each tank automatically resets back to zero after you fill the tank up and start the car without pushing the reset button. If you push the reset button, it also resets the avg. MPG, which I prefer not to do. Anyway, since the mileage didn't reset on its own this time, I'm wondering if something is wrong.

 

I was down to one pip, filled up with 9.6 gallons. So, I'm still wondering...

 

You're missing my point, though. I don't care to reset it. I'm only concerned because it is supposed to reset on its own and it didn't this time. This is the first time in almost 100 K miles that the mileage didn't reset to 0 after filling up.

 

Ok, now the plot thickens...after my first post on Aug. 14th, I drove the car for 500 miles and had one pip remaining. Therefore, Thursday night Aug. 22 I decided to get gas. MFD indicated my average mileage as 53.8 MPG over the past 2 tank fillups.

I started to pump the gas but it shut off early, I had only put in about 4.5 gallons! I know it isn't a good idea to top off the tank, but I honestly didn't think it could be full; so I tried to put a little more in. I gave a couple more squeezes, and put in .4 gallons more. Assuming the gas pump might be malfunctioning, I moved to a different pump. I started the car up, and this time the mileage did reset automatically to 0. At the other pump, I gave only one squeeze, and it immediately shut off, not allowing me to put in any more gas. However, the gas gauge was indicating only 8 pips, not full!

I then drove about 35 miles, and noticed the gas gauge had gone down to 7 pips. I found a gas station and this time I was able to fill the tank to the point that it registered as full. The mileage did reset again to 0. With the 3 fillups, I was only able to put in a total of 8.5 gallons into the tank...yet, when I started, I was down to one pip and had driven 500 miles. My past experience has been that when I'm down to one pip I can usually put about 10 gallons into the tank. Only in the winter does it shrink to the point that I can only put 8 gallons in.

So, now I have some questions/concerns:

1) Are the two issues related? (tank first not resetting to 0 and now having trouble filling it up all the way)
2) Why did the gas pump shut off with the tank only registering 8 pips? You would think it would shut off only if it was registering as completely full.
3) Wondering if this (problems with filling up the tank) is going to be a continual problem now, and if so, what to do about it.

I'm well aware of the shrinking bladder syndrome with this car, but what stands out to me is odd is that the tank wasn't full, only at 8 pips, but I couldn't fill it up all the way until I drove it 35 miles and went down to 7 pips. Also, I would expect that after having driven about 500 miles that it would not be filled after only 8.5 gallons in the summertime.

Thoughts/insights?

 

Nobody has any thoughts on this? Isn't it odd to not be able to fill up the tank when it is only indicating 8 pips?!