ASUS P5B-E Network Port issues

[shadowane]

I'm having a really frustrating problem with my network port on my asus P5B-E motherboard. Currently, I see the Local Area Connection going from available to unavailable over and over again. I'm not sure what is going on at all. Has anyone else seen this behavior on this board?

I had installed an IDE controller card to support my two IDE disc drives, but it never worked so I removed it thinking it was causing this problem. Now, the weird thing is that the port worked absolutely perfectly the first night I installed windows once I installed the drivers for it. The issue is that I'm not sure when this particularly problem really started so I'm not sure where to start troubleshooting it. I do know it isn't the router or the cable I'm using.

Please, any suggestions would be incredibly helpful.

Just as some side information:
My Network Connections:
1394 Connection
Connected

Local Area Connection
Connected -> Network Cable unplugged -> Connected (It switches)
Attansic L1 Gigabit Ethernet 1/100/1000

And disabled: (I have no idea what this does and so I disabled it since I thought it was causing the problem. Things work a little better without it, but it could just be my imagination.)
Network Bridge
MAC Bridge Miniport

I put an E6600, PNY Geforce 8800, and 2 gigs of corsair xms2 ram.

 

[cprince]

I'm thinking that it's either a bad cable or a bad solder joint between the Ethernet port and the motherboard. Try using a PCI Ethernet adapter and see if you still have the problem.

 

[VirtualLarry]

I had a similar problem with the gigabit port on one of my boards (possibly a Biostar NF4 board). It would constantly drop out the connection. It turned out to be some sort of incompatibility between the onboard NIC and the Linksys 5-port desktop switch that I was using. Plugging the cable into the switch on my router allowed the connection to stay stable. I have since replaced the Linksys 5-port switch with a Netgear 5-port GigE switch, no more problems.