My dealer has been relatively pro-active on this issue.
However, they really have no ability/know-how to fix the problem.
They have tried applying some buffering insulation (as per Volvo's instructions)
around the unit....very little difference....if any.
My dealer seems to be saying that the other model CD units will NOT fit
into a 2001 S40. And that the NEW S40 units are completely out since Volvo
has redesigned the dash.
Nobody that I have personally talked with seems to have this problem.
I can only assume that they do NOT listen to the CD player so much.....
since this problem happens DAILY on my car.
Again the question needs to be asked.....Why would Volvo put a CD player
unit into a car and NOT build in anti-skip technology?
I e-mailed Volvo on 07/06 to ask if they had any further ideas on this issue....
NO REPLY!
I e-mailed again on 07/14 asking for a reply.....again NOTHING.
As I said above....at least my dealer seems to be interested in resolving
this issue.
My guess is that the ultimate solution will be one of:
1) get a new car (I'm otherwise mostly happy with the car)
2) get an aftermarket radio (all of which apparently require special
bracketing)
3) live with it.

The dealer is gonna put in a new unit in another week or two.
I guess they are searching for a unit that is less sensitive.
That's the latest.