SSL-VPN Tunnel Down Logs Bug!

Hi,

We have fortigate 3950B v5.0,build0322 with multiple VDOMs. We realized that some SSL-VPN tunnel-down logs are in incorrect VDOM's log. For example: we have VDOM A and VDOM B. There are SSL-VPN users in both of them, lets say userA and userB. We saw that in VDOM A's VPN logs there is tunnel-down log for userB which belongs to VDOM B! How this could be happened? Is this a bug? Our customer which controls VDOM A ask us who is userB and how can it connect to my VDOM?

Thanks.