Hopefully, someone can give me a little insight on this.

I have one cable modem, attached to a Linksys single port router,
which then
goes into a switch and then to the server. No problem in that respect
works well.

The server has two NIC cards running connected to two switches, I
would like
to spread out the users over both NIC cards in respect to using the
modem for email, internet etc. I tested this and found it would work,
the server was giving me ipx type errors every few seconds, in respect
where the router was bound. Is there a simple fix for this or do I
have to
continue running all the users on one switch?

Any help would be appreciated.