After upgrade to 3.6, approvals are not displayed

Recently I upgraded RT from 3.2 to 3.6.
Everything works fine except there is a problems with the approvals.
They can’t be seen by the approving persons in the Approval section.
If they go to the approval ticket (which by default is owned by Nobody)
and take the ticket after that the ticket
will be visible in the Approval section.
It looks like a rights issue. I played with the rights to the Approval
queues but this didn’t help at all.
Any ideas?
Thank you very much in advance!

Valentin S. Chopov, CC[NDS]P
Senior Systems Administrator
Digifonica Canada Limited
(604) 628-8900 ext. 0058