[c-nsp] Strange trunk behavior

[Ghassan.khalil]

Dears,
I have 3400-me connected to a 2960 switch with interface vlan on each of them.
When configuring the link as access port on vlan 891 the interface vlan can reach each other.
But when configuring the link as trunk port with allowed vlan 891 the interface vlan stays up-up but the interface vlan can not ping each other.
Did anyone face this kind of problems with 3400-me or 2960 ?