this is not a problem as such,
but only a problem because you think it is.
Go and read http://www.faqs.org/docs/linux_network/
Linux Network Administrators Guide
You will find out that this behaviour is ok.
Maybe, depending on your exact setup, ip addresses, routing tabels, dns servers and gateway configuration you _might_ have a problem,
but you gave absolutly no info about these importand "details"