RAS setup problems

[#1]

I have been connecting to PlusNet using an internal ADSL modem.  Now however, my employer wants me to RAS in occasionally using a laptop and a modem/router (Netgear DG834G v4) that they have provided.
I have also attached my home PC to the router and all is well there, I can connect through the router with no problems.  The port number on the router shows solid green.  However, my laptop port number is showing solid amber and I cannot connect - I get the error message "Login failure due to : Remote host not responding".
The router config page on my home PC shows that there are two devices attached, with IP addresses.
I can ping the Default gateway from my laptop, and my laptop from my home PC.
I have tried swapping cables and swapping ports but the problem follows me, so there is nothing wrong with the cable or the port itself.
Does anyone have any suggestions please?  (I am not a hardware person, so please don't assume I know anything!).
Thanks.

[#2]

I wouldn't worry about the lights being different colours, its not indicative of anything untoward, its just design!
Most computers have network cards with either an amber, yellow or green light. I've seen a few with red ones, and many also have dual colours to indicate different connection speeds.
If its lit though, it means that the physical connection between the computer and router is working.

[#3]

First thing on both pc goto run type cmd then ipconfig /all and post the results for both pc,s.
Both should have the same ip range so if one is set to 10.0.0.1 the other should be the same apart from the last number. Both should have the same default gateway and dns settings
If you can ping the other pc the ip sounds ok so the fault may be with the dns or gateway.
It sound as if the router is set to only let certain pc's through. How did you set up the pc thats working did work have any software or anything to set it up? Your not logging into a gateway at work by chance or using vpn?

[#4]

Thank you to both of you for your replies.
I have spoken to an engineer at work today who confirmed that the amber light is indeed an indicator of speed.  My laptop connection is set to 10 Full which is what the amber light is showing me (I couldn't find any indication of this in the Netgear documentation). So, James, you were correct on that score.
The engineer looked in the logs on my PC and said that the laptop's software firewall was blocking me, due to the fact that the laptop thought I was in the office, not at home.  I needed to ensure that the Location setting on my Sygate Security Agent was set to VPN (you were right too, samuria). The engineer said that he had installed a patch to make sure that the laptop would set this automatically.
Tonight I have tried again - however, the Agent location is set to "Insecure" and I can't change it.  So, it's back to the office tomorrow and another talk with the engineer.