F# problem with duck typing

gistfile1.fs

type A = { Age: int;    Name: string }
type B = { name: string } with member this.Name = this.name

let inline name (x:^T) = (^T : (member Name : string) x)

let a = { Age = 29; Name = "Steffen" }
let b = { name = "Gary" }

printfn "%A" <| name a // doesn't work
printfn "%A" <| name b // works

// It would be even cooler if this property access helper would be created automatically.
// Even if this would break some old code.