Intermittent 'could not connect to XXX.XXX.XX.XX

Hi all

I have a very frustrating network problem. Hope someone can advise troubleshooting steps / resolution. Thanks.
At home, I have set up an IP camera wired to my (Linksys E4200) router. I want to connect to it from my remote location. To do this I have set up port forwarding on the Linksys at home to forward connections to the IP camera. The router is on a fixed IP address 212.XXX etc. When I try to connect from the remote location via http://212.XXX.XX.XX : portnumber in the browser bar, 9 times out of 10 it fails 'could not connect'
Occasionally it connects & I successfully log in to the IP camera.
If I ping the IP, I get timeouts
If I use PingPlotter I see that it takes 3 hops via my ISP & then get "Destination Address Unreachable" & 100% packet loss.
I am logged into Win 7 Pro 64 bit, had a Comodo FW, uninstalled it & use Win FW... still no joy.
The IP camera folk say it's set up OK, and it DOES connect but very intermittent.
*** ADDED INFO: When I use anybody else's PC, it connects perfectly every time... Just my PC...
I am unsure where the fault lies. Any ideas?

Disable or turnoff the Win Firewall... also check your AV product, as many also contain a firewall these days. If it has a firewall turn that off too.

Let us know how it goes...