vbulletin upgrade error from 3.7b5 to b6

[Pistils]

Hi guys, I've done this upgrade before, and I don't know what has changed. I've hit a stumbling block whilst trying to upgrade from 3.6. The majority of the upgrade goes smoothly with no errors, as it has done before. Unfortunately, I am stuck on this bit, although it may relate to a previous error. The problem is with the new album table. First off, the issue seemed to be that the 'public' column was missing when it was trying to change that table in a previous script. I created that column... Now I have this on the following page:

http://test.domain.tld/forums/instal...0b6.php?step=1



Step 1) Misc Table Alterations

* Updating bb_user table
* Updating bb_setting table
* Altering socialgroup Table (1 of 1)
* Updating bb_socialgroup table
* Altering picture Table (1 of 1)
* Altering album Table (1 of 2)
* Altering album Table (2 of 2)

Database Error Database error
The BreedBay database has encountered a problem.



Database error in vBulletin 3.7.0 Beta 5:

Invalid SQL:
ALTER TABLE bb_album CHANGE picturecount visible INT UNSIGNED NOT NULL DEFAULT '0';

MySQL Error : Duplicate column name 'visible'
Error Number : 1060
Request Date : Tuesday, June 3rd 2008 @ 04:30:38 PM
Error Date : Tuesday, June 3rd 2008 @ 04:30:38 PM
Script : http://test.domain.tld/forums/instal...0b6.php?step=1
Referrer : http://test.domain.tld//forums/insta...rade_370b6.php
IP Address : 77.68.5.71
Username :
Classname : vB_Database
MySQL Version : 5.0.22


Any ideas on what is wrong? The upgrade went smoothly about two weeks ago on another test version of the same site?

Thanks for your help in advance.