I own a convential Polar Express, the upgraded (Railsounds) tender, a built it myself with parts ordered from Lionel coach with announcements and a Lionchief engine and tender. On none of these do I hear what you are describing.
If Lionel is admitting that some bad ones got out I would badger them for a replacement tender or for them to fix it el freebo. Failing that you can pay someone to replace the board (if you aren't comfortable with that sort of thing) or buy the Railsounds tender or announcement coach which should be on eBay regularly.
Let us know what you decide.
Frank
