UVNC - LAN works, Internet doesn't

[xbx14]

I'm going a little mad - please help!
My setup is a SpeedTouch 536 v6, Linksys BEFSX41 Software 1.52.15, XPP and running RC6 as a service with MSRC4Plugin_NoReg.dsm.
I've also forwarded ports 5500 + 5800 + 5900 (all TCP) to my pc with IP 192.168.1.100.
I also has a DynDNS name that's tracked by my router.
I can PING my IP address of 169.254.-.- or my DynDNS name.
XPP Firewall has added Exceptions of Ports 5800 + 5900.
Inside my home, the VNCViewer works a dream, from any pc behind the router & modem. Outside is different - I cannot access from the internet via the JavaViewer or VNCViewer.
Running TCPView, I cannot see Port 5500 at all, but 5800 + 5900 are "Listening", with the process called "winvnc.exe:2640".
According to " GRC Shields UP", all those ports are "Stealth".
According to "PortQuery", if I query Port 80 using my DynDNS address, the port is "Listening", but when I use my assigned IP address of 169.254.-.-, Port 80 is "FILTERED". When I try Port 5800 on my DynDNS , it is "LISTENING" but with the IP address, it is "FILTERED".
I'd really appreciate any hints about what to do next!

[bevtech]

How are you testing this WAN connection?

[mattice06082]

Inside my home, the VNCViewer works a dream, from any pc behind the router & modem.

That would mean that your security software isn't blocking you.

Outside is different - I cannot access from the internet via the JavaViewer or VNCViewer.

This is what Bevtech is referring to. Are you trying this from inside your network? Some routers don't allow this.

Running TCPView, I cannot see Port 5500 at all, but 5800 + 5900 are "Listening", with the process called "winvnc.exe:2640".

You'll only see 5500 if you start the viewer in listening mode (using single click or PcHelpWare). If you aren't planning to use SC or PcHelpWare there's no need to set up port forwarding of it.

[xbx14]

I have a wifi'd laptop on the same network. It's the one running PortQuery, and I've also loaded the viewer and plugin to a usb memory stick that I run from that laptop.
Re Port 5500, I hadn't spotted it's for SC & PCHelpware, but I'll keep it because I've also loaded a SC exe to my website. When I ran the viewer in "Listen Mode" and ran SC from my laptop (again though, from inside my LAN), it worked.
I haven't so far been able to access the home pc using the viewer software, on my usb memory stick from outside my LAN.
I'm not sure what to try next!

[xbx14]

Success! I got a professional to come to the house. He advised me that 1) we needed to forward ports on the modem and also the router & 2) that I should have been forwarding from the modem to 10.0.0.1 (incoming port for the router) not 192.168.1.101 (IP address of the router). What I think he means is that there is an IP address of the device, and 2 ports for that device, 1 incoming & 1 outgoing. Anyway, I can now access my PC from outside the home, with DSMPlugin - so for now, I'm happy! Thanks for all the suggestions.