It sounds like the HP might be setup with Dynamic IP address support which is why the new router would pick it up so easily. The Rolands don't use this method and only support static IP addresses which is why a new router might not pick it up so easily. The new router is using a default IP address that may be different than what your Roland is looking for.
Example:
When you first setup the original router you may have only had the Roland so you set your network up as such
Router - 10.10.0.1
Computer - 10.10.0.2
Roland - 10.10.0.3
Then you got the HP and hooked it up. The router assigned it an IP address if it supports dynamic IP address
Router - 10.10.0.1
Computer - 10.10.0.2
Roland - 10.10.0.3
HP - 10.10.0.4
Then when you added the new router, it used a default IP address that usually is 192.168.001.1
Now your computer and the HP asked for an IP address and the router gave them one based on the default
Router - 192.168.001.1
Computer 192.168.001.2
HP - 192.168.001.3
Then when you hooked up the Roland, which doesn't support dynamic IPs, it said my IP address is 10.10.0.3 and the router says no that doesn't fit my parameters.
Router - 192.168.001.1
Computer 192.168.001.2
HP - 192.168.001.3
Roland - 10.10.0.3 - Router can't see this
This all assumes that the HP uses dynamic IPs. If not, you may have other issues. A quick fix would be to just change the Rolands IP address to start with 192.168.001.XXX keep the last number the same as what is already in there. Now change the IP on the software end to the same thing and see what happens.
