Postscript to this story... tonight I was able to connect a PC direct to my modem (bypassing the router) and access the Internet by power cycling the modem as suggested. And suddenly I can access memotoo.com just fine. Back via the router again, and it's unavailable again.
So the problem is my router!
Absolutely no idea why just yet.
Now I need to figure out why, and how to fix... (have an option or two to try)
Ill post here if I find the cause.
Thanks all for your help (with my first post)
Rob
---------- Post added at 21:07 ---------- Previous post was at 20:52 ----------
Quick bit of googling - looks like I might need to reset the MTU value lower. Shame cos on this (cheap VOIP ATA adapter) router, you can't do that. Pah