I've had those troubles too. In my case they were caused by the fact that TB doesn't backup address books with none default names (or doesn't do it very well.)
So I solved the problem by renaming my address book to TheBat.ABD, telling TB that it should use that new file, delete the old file from TB's address book config and backing up and restoring that new config.


In case your address book file has a non default name, you could copy the .abd file to the mail directory of your new system and opening that new address book:
Tools -> Address Book -> File -> Open address book -> the default open a file window appears.

It's possible that was a bug. I blamed it on the non default name for my address book, because I thought that was what solved it. But it's possible that my previous backups were made by older versions of TB.
Now that I think about it, it used to work with alternative names for the address book, because in the past I used to backup and restore the address book in order to compress it. (Deleting address book entries merely marks them as deleted, they're kept in the address book. The backup and restore process removes them from the file.)
So it's possible that there was a bug introduced somewhere and that I missed the announcement of the bug fix.