If you look in the tar.gz files you will find a large number of db files that are SQLite data base files. Theres a free viewer/editor on sourceforge.
com.google.android.gm-20110527-134920.tar.gz
Has a db named
mailstore.entourageedge.fake@gmail.com.db which is probably the problem.
When you resetup your account its looking for a database named
mailstore.YOUREMAILNAME@gmail.com.db
gmail.db in the same directory only has entry in the preferences table and thats the email address keyed to a column called first_time (currently set to 1)
2 thoughts -
1) Set first_time to 0 and see what happens
2) rename the db that is named after your email address and see if that works.
com.google.android.gsf also contains a database talk.db that has an accounts table which contains the email address used to set this up.