@Goner - thanks here's my reply to you...
Which IP number were you using ?
It should be the one in your router settings titled WAN (wide area network), not your LAN (local) ip-address. Or you can find out your 'outside' IP-address by visiting whatismyip.com from home.
Can you access your router and check the firewall rules to see if port 80 is actually forwarded to your DS ??
By the way ; are you trying to connect to your Internet IP from your LAN ? I've heard that some routers have problems connecting that way ; you should try it from a different location to really test this.
EDIT: maybe I'm asking and stating the obvious, but I don't know exactly what you tried ...

I used the WAN IP. I also accessed it via SmartPhone outside of the LAN.
Have checked my Router firewall rules and cannot see Port 80 listed anywhere but the problem is I dont know what to look for in the Firewall set up. Because I executed the DS to auto-configure the Router for EZInternet I have not manually changed anything on the router and I dont know how to "forward Port 80 to my DS" - not a clue other than where my router has the Firewall settings for port forwarding available for entry under 'Virtual Server' where I can specify the following fields: LAN IP Address \ LAN Port \ Public Port \Protocol Type
Loads of other Port forwarding is set up there by me for online games using both UDP and TCP but I see no obvious things added or changed by the DS auto-router configuration routine. Also under the DSM Control Panel/ Router Configuration I see lots of ports listed for Local Port & router Port but Port 80 is not listed. Someone once told me that forwarding and/or opening Port 80 is a massive security hole - isn't it? Anyway - does this make any sense? Is my Port 80 forwarded? Will doing it destroy my network security? How do I actually enter it into my Router and/or DSM? ....HELP?!
@jccguays - thanks here's my reply to you...
It's obvious too, but, have you opened the ports of the firewall inside DSM 4.0?
I would not know where to make that 'open ports' happen on DSM other than in Firewall but the DS is not directly connected to Internet that is why I have the router. There are no firewall rules set up at all on the DSM therefore.
Does me having the Autoblock feature switched ON within DSM have any relevance to this problem?
@Mike42dk - thanks here's my reply to you...
I my self are not completely sure that EZinternet always works as intended, so I always suggest that you forward your ports inside your router your self.
And the thing about checking if you can see the homepage inside LAN, is always a good thing, as stated in the other post not all routers support loopback, and if the router don't, then you cant see a homepage inside your LAN
I have no idea what you mean there sorry. If you mean can I see the main DSM login page from within my LAN then 'yes' I can if I type in the local fixed IP of the DS 192.xxx.x.xx
What the blazes is 'Loopback'?! What does it do?
Everyone - thank you - can you answer my new questions and determine from what I have said here what teh actual problem is with my set-up?