DotProject en MySQL 5

[lpmlpm]

Estoy instalando el proyecto DotProject, pero tengo un problema porque sobre MySQL 5 esta consulta no funciona:

Código SQL [-]
SELECT 
distinct tasks.task_id, task_parent, task_name, task_start_date, task_end_date, task_dynamic, task_pinned, pin.user_id as pin_user,
task_priority, task_percent_complete, task_duration, task_duration_type, task_project,
task_description, task_owner, task_status, usernames.user_username, usernames.user_id, task_milestone,
assignees.user_username as assignee_username, count(distinct assignees.user_id) as assignee_count, co.contact_first_name, co.contact_last_name,
count(distinct files.file_task) as file_count, tlog.task_log_problem 
FROM tasks, user_tasks 
LEFT JOIN projects ON project_id = task_project 
LEFT JOIN users as usernames ON task_owner = usernames.user_id 
LEFT JOIN user_tasks as ut ON ut.task_id = tasks.task_id 
LEFT JOIN users as assignees ON assignees.user_id = ut.user_id 
LEFT JOIN contacts as co ON co.contact_id = usernames.user_contact 
LEFT JOIN task_log AS tlog ON tlog.task_log_task = tasks.task_id AND tlog.task_log_problem > '0' 
LEFT JOIN files on tasks.task_id = files.file_task 
LEFT JOIN user_task_pin as pin ON tasks.task_id = pin.task_id AND pin.user_id = 1 
WHERE project_active <> 0
                                        AND task_project             = projects.project_id
                                        AND user_tasks.user_id       = 1
                                        AND user_tasks.task_id       = tasks.task_id
                                        AND (task_percent_complete    < '100' OR task_end_date = '')
                                        AND projects.project_active  = '1'
                                        AND projects.project_status <> '4'
                                        AND projects.project_status <> '5'
        AND task_status = '0'
GROUP BY task_id
ORDER BY project_id, task_start_date

En MySQL 4 todo funciona muy bien, pero en la version 5 esta consulta ( y solo esta consulta en especial) no funciona y da el error:

Unknown column 'task_project' in 'on clause'

La estructura de las tablas es identica en ambas configuraciones, y ya he revisado eso mil veces reconstruyendo la base de datos desde el metadata de la otra que si funciona, por lo que no se si se deba a alguna virgueria en el dialecto que haya cambiado en la version 5...

Cualquier ayuda es muy apreciada

Saludos

[[poliburro]]

FROM tasks, user_tasks
LEFT JOIN projects ON project_id = task_project


por que no intentas usar un inner join y asignarles sus alias?

FROM tasks As Tasks
inner join user_tasks As UsrTask
LEFT JOIN projects
ON UsrTask.project_id =
UsrTask.task_project