I know this issue has been dealt with several times, but I can't seem to find a good solution.
Anyways, we had our DSL modem die.  After getting the third replacement one in (along with several long tech support calls and a technician coming out), we finally got our internet connectivity back.
We were bridging the DSL modem to our router, which worked fine until the original one died.
Right now, we don't have the DSL modem bridged, but as the DLS uses 192.168.0.x for its LAN, and our router uses  192.168.2.x for its LAN, they seem to play nice together and we get internet.
But after doing that, I could no longer run EVO, with the problem being that my workstation has the wrong (or can't find the correct) IP address of our peer to peer server.  
I have rebooted the router, the computers, released and renewed the IP configurations. I also reinstalled Pervasive and disconnected and reconnected the network drive.  I can access all networked drives fine.
As a temporary fix, I added the IP address of our peer to peer server into the Hosts file on my computer to get EVO to work.  As we do not have static IP's and use DHCP on our router, this will have to be monitored to keep the connection right.
I have one computer (our purchaser's) that EVO works fine on- this is the only one that it seems to work on, and it is on the same LAN as mine.
The only difference I could find was that the DNS server address on my computer is the router IP address, while on the purchasing computer it is 8.8.8.8.  
I am hoping some network guru has some indication on what I am doing wrong.
The reason that I am not bridging the DLS modem is because it did not work on first two new modems that my ISP gave me, and they would not hard reset.  The third modem that I got was the same as my original one, so when my router connected to it I left it alone, as we had been without internet access for 3 business days.
I am not using the DSL modem's routing functions on my internal LAN, as it always dropped connections and I had the same issue with EVO not working.