Two customers have encountered this problem. CSP-5178 and CSP-12970.
It appears when trying to upgrade from 2.2.10 or prior straight to 2.6, 2.6 does not realise that this version does not have a bandana table and does not try to create it.
To workaround this issue, customers have to upgrade to 2.5 which will create the table then upgrade to 2.6.
I have provided the mysql backup and home directory as given to me by the customer.
Steps to reproduce
1) Install confluence 2.2.9 standalone.
2) Unzip the home directory (\\DEVFILES\Partha\Cases\CSP-5178\confluence.tar)to a location and point the standalone there.
3) Unzip the mysql backup (\\DEVFILES\Partha\Cases\CSP-5178\bkup.sql.gz) and import into mysql (Command to import looks like this, change names as necessary: mysql -u username -ppassword database_name < FILE.sql)
4) Modify the confluence.cfg.xml file to point to your imported db.
5) Start confluence and check that it works and you can browse pages.
6) Stop confluence
7) Install 2.6 and point to the old home directory
8) Start confluence. You should see table doesn't exist errors.