UBB.Developers Forums UBB.threads 7 Development How Do I? Passwords

I have been having some security issues on my boards from a competing forum lately and I finally figured out how they are doing it. They have been logging in under at least 1 mutual member that they helped with a pasword problem at their site and he happened to use the same password at ours. When I help someone and they forget their password or something and I edit their profile all I see in their password box is the astericks. Is there any way that they can get the other members password off of their forums and take the off chance they are the same as on ours? They are using 6.1.1 and have stated that they have read every pm from every member on our site. I have another admin that used the same password at both places.