Download latest full version with the link you got when purchasing vshare, unzip.

In the install folder, you will see

vshare-upgrade-1-2.sql (Only needed if you are upgrading from vshare v1).
vshare-upgrade-2-2.1.sql
vshare-upgrade-20070530-20070625.sql

Open vshare-upgrade-1-2.sql and compare the table fields with your database in phpMyAdmin. If you don't have the fields, you need to run the SQL.

I think you need to run vshare-upgrade-2-2.1.sql and vshare-upgrade-20070530-20070625.sql

After running both (in the order), you need to call install/upgrade.php