BB Software :: Denies Access To Existing Accounts?

I switched from a Blackberry Curve to a BB Torch 9800, transferring all data from the old to the new BB via the BB Desktop Manager. There were 4 internet mail accounts on the old BB, and icons for the same accounts are now present on the BB Torch 9800. Problems: (1) Even though there are the icons, I cannot send or receive e-mails on the BB from/on any of the four accounts. (2) So I went to the set-up icon, selected "e-mail accounts", the BB did the "connecting to e-mail settings", and a log-on page to existing user accounts appears, asking for user name (the e-mail address, presumably) and the respective password. But here is what I cannot resolve: No matter what I type in the user name field and the password field, the BB always says "The user name is invalid. A user name must be at least 4 characters". A blatantly absurd reaction, for none of my user names has so few characters.