Thank you Rudi!
Been testing in the past days and I can now confirm that it works again
I've noticed that there's a 12sec delay when I accept the client connection and get to see it's screen. this is only in Win8.1 client, Win7/XP works great, Win8 couldn't test.
Latest update is giving me some problem related to UAC on Win7/8/8.1, Vista not tested.
Client can connect with any host described on helpdesk.txt but after establishing the session I can't interact with those windows that need Administrator permission (task scheduler, odbc data sources, installers ...