Connecting a wireless webcam with Dyndns

[#1]

I am getting very frustrated.  I bought a wireless webcam a year ago and set it up without any problem and it worked fine.  I could view the webcam through the internet using dyndns from remote locations without problems.  Then the novelty wore off and I stopped using it.  Now I really need to use it for the the purpose for which I originally bought it, but I cannot get it to work.
It works fine on the LAN, but I cannot connect remotely.  I am running Windows XP and am registered with dyndns.  For the time being, I have turned the firewall off.  I have a Linksys WAG354 router.  Can anyone suggest what I am doing wrong ?
I have checked that I have a dynamic dns and dyndns is registering the correct IP address.  So that should work.  But I cannot connect even to the router !
I connect to the router without difficulty with http://192.168.1.1. ; But I would have expected also tyo be able to connecrt to the router using my dynamic ip address.  But if I input http://87.112.163.68, I get nothing back.  That ip address is the same as shown under Admin in the router.
Something somewhere presumably is blocking access because surely I should be able to log into the router using 87.112.163.68 ?  (I hwill now shut down and re-boot the router for security).
Any help please ?

[#2]

Have you checked if the Plusnet firewall is off?

[#3]

Good idea, but I am afraid it makes no difference.  I have now turned off the Plusnet firewall, the ZoneAlarm firewall and the Windows firewall, but I still cannot access the router by using http://**.***.***.***. ; I have checked the ip address is registered with the router correctly and I have also checked that it is registered with dyndns correctly.  The only thing that works is "pinging" the ip address - no faults.  So ping works ok.
It is bizzarre.  I would have thought that if I http:// the ip address, I should at least get the same response as 192.168.1.1. or have I misunderstood that ?

[#4]

Are you using the same router when you had it working before?
It sound like a loopback problem. Some routers will not handle the public IP when requested on the LAN side, others will have a loopback that is disabled by default. One way around this is to use a proxy like http://anonymouse.org/anonwww.html

[#5]

Thanks.  I have just tried that and it makes no difference.  I still cannot access the router by using the ip address.  Grateful for the idea neverttheless.

[#6]

You have set up port forwarding correctly?

[#7]

Quote

It is bizzarre.  I would have thought that if I http:// the ip address, I should at least get the same response as 192.168.1.1. or have I misunderstood that ?

Unless your router has Remote Management enabled ( manual page 26 ) it will not respond on its public IP

[#8]

I think that I have discovered the problem after hours of fiddling.  Basically, the Network on my laptop is completely fouled up.  It is not seeing other uPnP devices on the network and now, following my fiddling, it has ended up in a total mess.  How do I delete the existing networks and start all over again ?  I am sure that the root cause lies there somewhere, because on my desktop computer I can see the IP camera without difficulty but on the laptop, it will not access it.
So, rather than re-installing XP, how do I just get rid of all the networks and start bilding them from scratch ?

[#9]

After hours of toil, I have discovered the culprit - it was Avast ! anti-virus software.  I did stop Avast and Zone Alarm before but it made no difference.  I do not know what I did last night that was different to the time before, but at last I know the cause and have been able to change settings to stop it happening.
Thanks. for the help.

[#10]

I have finally cracked the whole thing including port forwarding and setting up Dyn alias with DynDns.  It is going to be extremely useful to monitor the camera remotely from anwhere with a wifi connection or even mobile phone.
I have learnt a lot about setting up the modem and camera itself - including how to overcome faults in the UPnP software as a resul and would be willing to share it with anyone who maybe trying to do something smilar.  It certainly is not as straightforward as it appears.

[#11]

Could you could give a detailed tutorial of you accomplished this, I have tried port forwarding in the past without success...