Your DSL provier is bridging this back to you over an ATM PVC and you're mapping the PVC to a BVI with an IP in the hub right?
If your DSL provider is handing you an IP then ignore this post.
On the 1841, put an IP in the same subnet on an Ethernet interface.
For example:
On an 8510 switch:
atm pvc 2 32 interface ATM0/0/0 2 32
On "hub" router:
interface ATM3/0.32 point-to-point
description *** xxxxxxxxxxxx ***
bandwidth 640
bridge-group 232
bridge-group 232 spanning-disabled
pvc 2/32
encapsulation aal5snap
interface BVI232
description *** 640K DSL xxxxxxxxx ***
bandwidth 640
ip address x.x.x.1 255.255.255.0
ip route-cache flow
On remote 1841 router:
interface Ethernet1/0
description *** 640K DSL to xxxATM3/0.32 - BVI 232 ***
bandwidth 640
ip address x.x.x.2 255.255.255.0
half-duplex