Can't connect to network share with the IP address

I can't connect to any of my computers or nas drives on my network with there IP addresses. But if i use there names it works fine. I wouldn't care about this problem but i am also trying to connect over a VPN program Hamachi with doesn't work with names very well and likes IP addresses only.

This problem only seems to affect the network shares because i can remote desktop in to the computers fine wiht just there ip addresses this also works on hamachi as well

I am using a HTC Fuze
and the computes OS, Windows Vista Enterprise, Windows 7 RC, Windows 2008 Server

I will try an XP machine when on becomes available

I am using my Wifi connection and my 3G connection (with Hamachi) and using the standard build in file explorer to access (or attempt to access) network shares

Thanks