No, Windows Home Server is limited to a maximum of 10 users; see
this blog post for more information on why. If you need more you could always set up a second home server, since two or more will coexist on a network. You'll have to pick just one for remote access however.
Also, your server is still running the original RTM code if the version number you quoted is correct. You should run updates (using the
Update Now button in the Console) repeatedly until no more are found, as there have been a couple of serious issues fixed since RTM.
I'm not on the WHS team, I just post a lot. :)