We sure as heck run the 767s and 757s dirt low on fuel.... Perhaps the folks at fort widget aren't sure what they can get away with?

And by the way... if there's too much gas and the plane hasnt fueled- we have this device that is called a telephone. I suggest using it. Dispatchers tend to answer.

Also, if it's consistent- are you CORing it? A problem doesnt exist unless it's documented.