Also had the same problem with the same set-up. VPN connected fine, but couldn't connect to internal services.I Found that the only way to get this working was to add "sysopt ipsec pl-compatible" command.
Cisco's view on the command is this
"Note: The PIX Firewall currently only supports IPSec on the outside interface. Although the PIX Firewall currently can simulate the Private Link inside termination with the use of the sysopt ipsec pl-compatible command, the termination on the inside interface is not a true termination. For more information on the sysopt ipsec pl-compatible command, see the sysopt command page."
The only other way I found (without using the above command) is to use Network statics or static translations to the devices you need to see on the inside network.
Hope this helps
