Thanks for all the responses I received on this.
I crawled under the rig and had a look around.
The fill hose and vent hose looks like it is not cracked or leaking.
However, I did notice that what looks like a small amount of gas has seeped from somewhere on top of the gas tank part of the way down the side. It would seem to suggest something similar to the last person responding that it might be a cracked vent line on top of the gas tank which I cannot see without taking the whole gas tank out. That is something that will have to wait till I get home.
thanks again for everyone's response.
Steve