@Tshepang, one thing you definitely need to do is configure a bridge interface (br0 below) on the host. Here is the current version of my /etc/network/interfaces. VirtualBox is the only reason I have it configured as a bridge. Do you have it set up like this? I got this from somewhere on the net. I forget where, but if you really want I can probably dig up a link for you. I took a look at my Fedora 14 VirtualBox guest, and it doesn't look like I configured any networking stuff there. So try making this change and see if it makes any difference. On my machine eth1 is the main ethernet interface.
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
#allow-hotplug eth1
#iface eth1 inet dhcp
auto br0
iface br0 inet dhcp
bridge_ports eth1
bridge_fd 0
bridge_maxwait 0