[horde] Problem upgrading horde-webmail from 1.2.5 to 1.2.6

[Marco]

Hi,
 I tried to upgrade from horde-webmail-1.2.5 to 1.2.6.

The script 'setup.php' returns this error:


[ ERROR! ] Updating the tables failed. Please see the manual at docs/INSTALL
           for how to setup the database manually. Error messages
MDB2 Error: constraint violation
_doQuery: [Error message: Could not execute statement]
[Last executed query: ALTER TABLE horde_sessionhandler ADD PRIMARY KEY 
(session_id)]
[Native code: 1062]
[Native message: Duplicate entry 'ul43q45euhbno8audatmotp0s2' for key 1]


This doesn't happen from 1.2.4 to 1.2.5.
I tried to delete mysql entry duplicated, but I have too many
entries duplicated.
My horde_sessionhandler is correctly set to InnoDB.

For this upgrade it doesn't matter if the script fails,
because there are no DB changes.
But I could have future problems if the script has to change DB...

For now the only way to do the script work is to delete
all horde_sessionhandler records.

Regards
marco