XP Limited Connectivity with D-Link DSL-G604T

I have two XP machines, connected together for sharing documents using D-Link DSL-G604T.
http://pcgenie.co.nz/images/products/DSL-G604T.jpg

They are connected to the D-Link DSL-G604T, using ethernet cables. They have been happily working together till now. Recently I had to unplug them all to replace the carpet. Now they are all plugged back in as they were before.

After this, one of the PC was able to connect to the network and the internet at the beginging. The other PC was complaining that there is limited or no connectivity. So it couldn't see the other PC or have access to the internet.

I unpluged the D-Link DSL-G604T, a number of times and powercycled and now both PCs say that there is limited or no connectivity. The green Status light in the front of D-Link DSL-G604T is blinking and the green ADSL light is solid. From the documentation I understand this means it works OK.


But why do the PCs say there is no connectivity? Is the my D-Link DSL-G604T dying?
Thanks