I actually thought about it when I saw your thread, that's what made me think of this issue. Sorry about your account I've never had ampersand problems, if that helps any!
I've used plenty of the approved characters as well -- as highlighted by my OP, I'm talking about specific issues with the $ only. Don't know how recent, but I've had the problem for the past couple of years, off and on.
OMG. -facepalm- I think you're onto something... @(you need an account to see links) Are you using numbers as well, or just letters?