Thunderbird craps on my head

I hate to be down on Thunderbird, which I use as my default mail client in Windows XP. But today I turn on the box, start Thunderbird, and things don't go well.

Since I have two IMAP accounts plus local folders set up in Thunderbird, I use the "Master Password" feature so I don't have to enter passwords for each of my accounts, and I figure I'm adding some measure of security that way.

I type in my Master Password when prompted.

It doesn't work.

I type it in about 10 more times.

Still nothing.

So I try to CHANGE or get rid of the Master Password. It seems that you can't do that without knowing the Master Password in the first place.

Are my local folders locked forever? Will I have to completely reinstall Thunderbird?

Answers: No and no.

It is possible to remove the Master Password without knowing it:

If you have lost or forgotten your Master Password or you want to disable the feature, you can reset your master password. Upon resetting, you will lose all the stored information in the Password Manager as this is a built-in security feature to prevent people from simply resetting your Master Password to gaining access to your passwords.

Thunderbird 2: Choose Tools - Error Console, paste the expression: openDialog("chrome://pippki/content/resetpassword.xul") and press the Evaluate button. That will open a dialog asking you if you want to reset your password.

Sure enough, that worked. I reset my Master Password, but I'm still in the dark as to why Thunderbird broke in the first place.