Problem with Fork/Join

I am having some problems with the Forks / join when I have assigned swimlanes, and I can't figure it out yet. Perhaps you can think of something.
I have a simple graph with 5 tasks. Task 1, Task 2 Task 3 Task 4 and Task 5. I also have a fork and two joins.
The situation is like this:
The process starts and then launches a Fork that runs 3 tasks, Task 1, 2 and 3. which have different swimlanes associated to them.
of these 3 tasks, Task 1 and Task 2 converge on Join 1, which continues the thread to task 4.
Task 4 has a transition to Join 2, which is responsible for closing task 3 (originally launched with Task 1 and Task 2 but not yet closed).
Once task 3 and 4 finish, the flow should continue.
Theoretically, it seems to be fine. Practically, the Fork / Join work if I do not assign swimlanes. But when I assign different swimlanes to the initial tasks T1 T2 and T3 the process gives problems, it won't let me close the first fork. Because Task 1 and Task 2 have different swimlanes (it is giving me a foreign key error between the active task table and the swimlane table). From what I see, it wants to delete from the active task table after finishing a task, but it does not delete from the swimlane table, thus the foreign key error emerges.
This is the error.

Could not delete:
org.jbpm.pvm.internal.task.SwimlaneImpl # 164; nested exception is org.hibernate.exception.ConstraintViolationException