Fuel Price Question?

ok, so i set up a route (this happens often) and then i come back a few hours or days later and its losing money, it seems the fuel price has shot up... is this normal? a glitch? something i can avoid by crossing my fingers spitting and running around the house naked three times?

anyway, came back today to look at some routes and found a bunch in the red, i resubmit my prices (hit save) and they change back to in the black. here is a breakdown.

Operating Revenue
Ticket Sales (F) -
Ticket Sales © $3,984
Ticket Sales (Y) $22,704
In-Flight Service -
Total Revenue $26,684
Operating Expenses
Fuel $18,112
Flight Crew $456
Cabin Crew $100
Ground Crew $260
IFS Cost $707
Landing Fees -
Other Taxes and Fees $8,120
Total Operating Expenses $27,748
Operating Profit (Daily) $-1,064

after i save again

Operating Revenue
Ticket Sales (F) -
Ticket Sales © $3,984
Ticket Sales (Y) $22,704
In-Flight Service -
Total Revenue $26,684
Operating Expenses
Fuel $4,372
Flight Crew $780
Cabin Crew $172
Ground Crew $260
IFS Cost $708
Landing Fees -
Other Taxes and Fees $8,120
Total Operating Expenses $14,420
Operating Profit (Daily) $12,264

i mean, if the true costs of the route is 18k, thats fine i just wont fly it. but when i first create the route it is 4k.

i didnt know if this was a bug or not, or if it has been reported. its happened to me in almost all the 3.1 worlds. but typically only happens on short distance flights with turbo props, although i guess it could happen with others i just notice it on these routes because the profit margin is so much bigger.

anyway, this is DFW-ITC in a F-27 its 329 miles, so... yeah. thanks