10/100 NIC

Hello All,

I just finished upgrading my home network to 100Mbit. I installed 10/100
cards in all my machines (2 Windows boxes and 3 Linux boxes) and installed a
new 10/100 Hub. However, when I FTP files to the any of the Linux boxes the
upload speed isn't any faster than when I was running only 10Mbit cards, the
transfer speed indicater in the application shows the same transfer rate.
Also, when I start my VNC session against my Linux box, the refreshing of
the KDE screen is not any faster either.
When I copy files between the two Windows machines, the process is a LOT
faster than before. This indicates that the Windows machines are talking to
each other at 100Mbit, but the Linux machines still seem to be at 10Mbit.
The hub shows all machines linked at 100Mbit.

Is there some way I can tell if the cards in the Linux machine are actually
receiving/transmitting at 100Mbit?
Is there a setting I must activate for Linux to utilize the new 100Mbit
connection?

Any help would be greatly appreciated.
Peter