Yes, that problem (sometimes called a whistle or a siren depending on the severity of the noise) has been noted by many owners and Volvo is reported to be working on a fix due out in April. Check with your dealer then to see if it has arrived. If the dealer doesn't know, you can try Volvo's customer service hotline at 800-458-1552. In the meantime you can console yourself on the Sweedspeed, VolvoXC or Edmunds forums which aren't dead like this one. How do you like the 90 otherwise? The other major complaint seems to be the gas mileage which is nowhere near the rated 20 highway.