Can't access unite even with http://localhost:8840

I have a machine with Opera Unite on it and I can't access Unite services even when I try and use http://localhost:8840. The service is on, I can get to it all from Opera, but no other browsers.

I have tried restarting the app, reinstalling the app, etc...

What are some things I can check to trouble-shoot this problem?

If I'm within the Opera browser it works (this IS with http:// and not unite://), but from other browsers on the same machine, I get intermittent problems (503 or sometimes just a 'can't find this site') but it never works properly.

There was a time when I first installed that it worked properly, even through the Unite proxy, but with no changes on my system it just started to fail in this manner.

My other computers all appear to be working through specifying 8840. FWIW none of my installs since the first have had the Unite proxies working correctly ever but at this point I just want to get the base service working.

Any guidance appreciated, thanks,

Randy