20% packet loss with re0 in gigE mode vs. 0% in 100BT

I do not think this is a very acceptable performance, but I have little
knowledge of ethernet drivers on FreeBSD to identify issues.  I'd say
any packet loss in the configuration I was testing would be
unacceptable.  Where to begin?  I'll do what I can to help fix this.

The tests were with udp packets of size 1316 on a quiet network.  As
explained in previous emails the only network combination that has loss
is when the re0 is in gigE mode under FreeBSD.

Cheers,
Sean