"Odd" Cisco 1721 Problem

[mongoosse]

I have a customer with a network of 4 routers. The appliaction is a VoIP network with the device doing the VoIP compression. The routers just provide the network. Each router has a 192.168.X.0 address as follows:
192.168.1.1
192.168.2.1
192.168.4.1
192.168.5.1
The routers are using RipV2

The "odd" issue is that I lose connectivity from 1 device (192.168.1.10) every 1-2 weeks and I can only restore the connection by restarting the device.
From any PC on the 192.168.1.0 network, I can ping the far end VoIP device (192.168.2.10) and any other PC or device in the network. And all sites can ping back to all devices.

The VoIP device (192.168.1.10) can ping any local PC, any router 192.168.x., but not the far end VoIP device (192.168.2.10).
SHOW ARP shows 192.168.1.10 in the table with 0 minutes of life.
SHOW IP RIP DATABASE shows all routes in the network.
Even setting up a static route does not allow the 192.168.1.10 to ping 192.168.2.10. It can ping to 192.168.2.1 and dies. Any PC on the 192.168.1.0 network can ping to the 192.168.2.10 device.

I originally suspected that the destination was removed from the RIP tables in the router but if I can ping to the remote router and it fails I would suspect a problem in that router except, that all other devices can ping the remote VoIP device.

Any ideas?
Thank you.

 

[JOAMON]

Can you post 192.168.1.0 and 192.168.2.0 router conifgs ?

 

[schofs]

Use tracert to see how far the packet travels before disapearing the problem may be on one of the four devices