Tony, I had exactly the same issue with my wife's 2008 Volvo S60, on which the plastic that surrounds the connector developed a crack and fuel was sipping out.. (BTW, on the S60, the fuel tank is underneath the rear seat, so you can imagine the smell..)
The cracked plastic cover was a part of the fuel pump, therefore I ordered a new FP and a the large O-ring that sits between the bottom of the plastic cover and the fuel tank.
I would suggest you to lube the large O-ring with silicone grease so when you are tightening the collar you don't squeeze the O-ring.
Note: Before you loose the collar, I would suggest first to blow compressed air and properly clean everything! Otherwise you will be dropping dirt and grime inside the fuel tank..
