I decided to upgrade VirtualBox because the newer versions have much better support for networks that allow virtual computer to be visible on the real network.
But after upgrade I encountered the error
"HostInterface': The attribute 'name' is required but missing."
It seems others have had similar issues
http://forums.virtualbox.org/viewtopic.php?p=58720&sid=f3759d4d938c30120... [1]
I resolved this by deleting this entry:
<HostInterface/> from the config file, in my case this was
.VirtualBox/Machines/WinXP/WinXP.xmlAfter this the virtual machine worked fine - and the new network settings are great.
Links:
[1] http://forums.virtualbox.org/viewtopic.php?p=58720&sid=f3759d4d938c30120502ad5610833caa