I was referred here by the Thunderbird support forum. I am using Thunderbird for U3 on a U3 drive and TB suddenly lost track of my account info (prompting me to set up a new account upon startup). None of the solutions I've seen here and at the main TB support forum seemed appropriate on the U3 drive (i.e. could not find ini files or other files or folders referenced in solutions or preventive measures).
I finally fixed my problem by recreating each of the 7 mail accounts that I monitor, then using mailbox import to import the SENT, INBOX and DRAFTS mailboxes from my original accounts. So, I'm a happy camper again.
But,I was about to deploy U3 + Thunderbird for U3 to all of the people in my office. I'm reluctant to roll out something that might become a support nightmare. Is there a way to prevent this loss of profiles on the U3 version?