This issue might be occurring if the Viewer's configuration file or some other files were somehow damaged/corrupted (perhaps, by some antivirus/firewall software activity). Could you please try the solutions listed on this Knowledge Base page and see if any of them help to resolve the issue?
... or do I have to reboot my local PC every time I config the view mode? Because it seemed like no matter what settings I chose - the remote screen always looked the same - with scroll bars to see everything.
I'm glad to hear we were able to help and it works for you now!
I've tried changing the view mode, but none of the options worked. I tried checking and unchecking "constrain proportions" and that didn't work either.
Could you please try setting you View mode to Stretch mode and see if this helps to resolve the issue? This can be done in the Connection Properties window -> Mode tab - this should save your settings for a specific remote Host and apply them when you connect to this Host next time.
Please note that the changes made in the Default Connection Properties window will be applied to the newly created connections only, i.e. to all Hosts that you add to your address book after making the changes in the Default Connection Properties window. This means that the settings in the "Default Connection Properties" window will not affect already existing Hosts in the address book.
In order to change the View mode for the already existing Host, please change it on the Mode tab in the regular Connection Properties window which can be invoked by right-clicking the Host in the address book and selecting Properties.