NR041 Lynksys- Switching from one service to another, now won't route?

[starwind]

Here's my situation. I orginally set up the linksys router to 2 previous providers with no problems, using the disc that came with. Computers I ran then had XP only. SBC service was what I used 1st, then I moved to MN and used Qwest service there. SBC got bought out in MO and when I returned here, I had to use AT&T DSL. This service I can't get my linksys router to route. I had changes over the year. One pc now runs Vista, but was able to connect through the router's previous settings under qwest. I set up the router and try to tag my 2 pcs and the connection, and get nothing. I tried every possible setting change I could think of. NAME and PW is needed which is saved on the modem itself, like I had on my previous modems, but doesn't access for some reason. I can connect just fine strait, but can't route the service. My thoughts on this: Using a low band width DSL which is at like 700 kbs and due to the restriction of speed, it might be messing with the signal for the router to pick up on. (kind of far fetch) The moedem is the culprit. Motorola speedstream which is like a little grey pos of a modem, smallest I ever seen for dsl external modems. Line checks by service tech helped fixxed a minor connectivity issue, but still unable to route the service. I tried bridging the modem, making the router be the PPOE connection to give name and pw and still no response. I think my router is telling the modem ... um well maybe it's just me cursing under my breath. Any ideas or views on what can be done or if I'm pretty much hitting this one on the peg, I'll try anything as long as my pc don't blow up/