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Issue with Serial Connection between remote sites

I'll try to keep this brief.  If you need any additional information, let me know. 


Basically, we have a 56K connection to one of our remote sites (it's all that's available). We recently purchased a new 2911 router and are consolidating a couple of routers into just this one.  We purchased a 56K CSU/DSU WIC to go with the new 2911 router.  This WIC is replacing a Cisco 1602 with an onboard CSU/DSU.  The remote is also a 1602.


Here is the output from the sh int Serial 0/2/0 on the new router with the WIC. I just reset the counters and started the process over and things are working great, but what's odd is that the connection will be just fine for perhaps a day and then start to go downhill.  The total output drops starts to shoot up as do the carrier transitions and interface resets, but not quite as much.

interface Serial0/2/0
 description YANKTONSG_LAN
 ip address

 service-module 56k clock source line
 service-module 56k network-type dds
 no ip route-cache


And here is the sh int Serial 0 from the remote router as well as the config for the Serial interface.

interface Serial0
 ip address
 no ip directed-broadcast
 no ip route-cache
 service-module 56k clock source line
 service-module 56k network-type dds

I repeatedly called the provider to have them check the circuit at the remote location and that has tested out just fine. Any ideas of what I could start looking at?