Frequent error: The city pct must be an integer

[EJEvo]

Any time I'm entering multiple fill ups for a vehicle, I frequently get the error "The city pct must be an integer". This value is set by a slider, which seems weird to complain about as Fuelly itself is generating the integer to be used. This makes me go down to the slider, change the value and the put it right back to where the value started originally, then attempt another save of my fill up. This will fix it for the fill up, but the next one will do the same thing.

Anyone else experience this? It's maddening.