Bad news...
Drive Wifey's XC60 for a long-ish trip on Friday evening and it still has axle-ping. It is nowhere near as bad as it used to be, which tells me that the new axle bolts have made a difference, but it certainly isn't fixed.
I'm guessing that the splines on the outer CV joint shaft, or in the hub have worn, which is still allowing some movement.
Hey-ho - it's only money.....