Well, the tunnel is established. We know this because you've done the ping test and we know that traffic is being encrypted and shunted across the VPN tunnel. If you've done the ping tests correctly (With the non fragmentable flag and specified packet size set) and have adjusted the MTU using DrTCP (From dslreports.com) your system should also be setup correctly for Windows networking to work.
Which means, at this stage, it sounds like a Windows networking issue, rather than a VPN one.
Can you reach the machine by IP? E.g. \\192.168.0.1 ? Also, try running
nbtstat wrote:C:\Documents and Settings\pascalv>nbtstat -a 192.168.0.60
where 192.168.0.60 is the ip of the machine you are unable to reach. See what type of response it gives you back.