Upgrade TFS 2005 to 2008 : Workflow 'Quiesce DT' failed! ExitCode = 8000

Whilst attempting to upgrade the test TFS 2005, I got a rather nasty error box appear. Examination of the logs was a touch difficult (wood for trees), but managed to spot the the 'Quiesce DT failed'. Further digging and I spotted "No associated service account for role TFSEXECROLE". Not entirely sure what this meant, I found this post which is exactly the same issue. The bottom line is that every TFS database must have the TFSService account assigned to the TFSEXECROLE database role. The following SQL helps identify this, run it against each TFS database until the incorrect one is found :

SELECT dpMember.name
FROM sys.database_principals dp
JOIN sys.database_role_members drm
ON drm.role_principal_id = dp.principal_id
JOIN sys.database_principals dpMember
ON dpMember.principal_id = drm.member_principal_id
WHERE dpMember.Type = 'U'
AND dp.name IN ('TFSEXECROLE')

The add TFSService to the role.