If it doesn't turn out to be the venting, try popping the tank up, switching on the ignition to allow the fuel pump to prime whilst watching the areas closely around the throttle bodies. Probably best to do this when the bike hasn't been ridden as you stand more chance of noticing fuel escaping. Before priming, give the area a good wipe down with a cloth to help make it easier to pick up on any leaks.
Reason I say this is that I had a similar fuel smell issue after switching off and eventually traced it to the right hand side of the throttle bodies. I found the smallest of leaks coming from where the connectors are mounted on the right hand side. This section is a seperate bolt on to the main throttle bodies which uses two star headed bolts. The lower bolt had seemingly vibrated loose very slightly and when you primed the engine you could see a small line of fuel leaking through onto the main surface of the bodies. I pinched it back up and haven't had a problem since.
Hopefully yours is the venting. Good luck :thumbup