Hi,
What kernel versions are you running ? There was an issue in the virtual interface drivers that could cause this; This was fixed on 2006/02/05 on the netbsd-3 and 3-0 branches.
I'm using generic XEN0/XENU kernels distributed with 3.0. I will try to recompile them using an updated source tree. Of course I tried to search the archives before posting, but I probably missed it.
Thank you. Best regards -- Matteo Beccati http://phpadsnew.com http://phppgads.com