Another "Cable disconnected message"

Hi everyone, this is my first post here but not the first time viewing.
Anyway this is my situation. im trying to get a new(new to me) system online, im getting the cable disconnected message and no link lights on the system or the router. I'm using a Linksys BEFSR41 4 port router connected to a motorolla cable modem. now i know everyone has seen this time and time again on post but this one is a little different and really confusing to me. This is what ive done so far. Ive swapped cables, swapped ports on the router, reset both modem and router, set duplex speeds and changed the power options in device manager, updated BIOS and the network adapter. the card is recognized properly and windows (7 Ultimate) states that there are no problems. Easy enough as i know the cables work, i know the ports are good on the router (another system, xbox360 and PS3 connect with no issues in all ports) so i pulled a NIC from the spare parts bin and windows installed the drivers and i still have the same network cable disconnected message. i plug it into the modem directly and i have a connection on both the onboard and the PCI NIC i put in. So it leaves me to belive that its has to do with the router or the system itself as the PCI is not recognizing a connection. Im leaning toward system due to both NICs not functioning but im still not ruleing out a compatability issue with the router. I know ive done all i can do at this point but if anyone knows why this is happening or if they know of a resolution id love to hear it.

Cheers