Hey, I get to resurrect this thread.
I had all the same questions as everyone else after doing about 250mi today back and forth from home to Loma Linda for my fiancée's dentist visit. Couldn't figure out when I filled up this morning why it only took about 7 gal when the gas gauge was where it was, and couldn't understand the thing telling me I only had 100mi left when we got home with the size of the tank I had read in the user manual.
Talking at Wendy's we postulated that maybe it's the reserve thing. The light on my Ninja comes on with a gallon in the tank, enough for about 40-50 miles, and my buddy's Electra Glide comes on at half a tank, so I guess we have the same phenomenon here. Glad to know I'm not crazy and the manual's not a typo.