OSPF Oddity

I was playing with OSPF over a PPTP tunnel and after a bunch of learning, I got it going, and its pretty cool.

In my routing table for router A, 10.2.23.0/24 shows in the list, and I can access .1 and .4 on it, but devices on .3 and .6 dont respond? although on router B, where they are physically connected I can ping them fine and everything works.?

Any ideas?

EDIT: on router A I can ping them from the router directly, but not from any computer behind it, either NAT or non NAT, I figured if I had problems pinging .3 or .6, Id not be able to ping and use .4 at all?