Shutting down kernel 2.5.6x... and devices...

Hello,

Each time I try to shutdown my machine now running kernel 2.5.68, I have messages stating :
unregister_netdevice: waiting for tap0 to become free. Usage count = 2

for ever, and the machine doesn't stop/halt/restart.

Trying to kill the process using tap0 is not enough, it seems to be "unkillable"... (it is the tool named vtund).

What is this ? It is perfect with 2.4.x

Regards,
Paul