Thanks for the tip. As for discontinued, on URC's site it is not listed anywhere, nor under disc. nor under any other category. It can be found only under the old news and some dead links, like to the MX-880 manual!!!
It looks more of an abandoned then on discontinued product... sadely.
Edit: on some post from 2007. is said that software for MX-810 was never on URC's site, always from dealer... wow, that's complicating the things even further as time goes on...