I amhaving the same problem. I can ping the internal and external interface from the inside (I took out the Stealth Rule to verify this), I can ping the inside and anywhere outside from the fw machine, but I cannot go from the 10.0.0.0 net inside to the outside. The log viewer shows that it is accepting the packets, but no replies come back. I'm sure this is a routing problem, I just don't know where.