For those of you being depressed, because UltraMon 3.0.x Beta isn’t running under Windows 7 Beta, I say: “Don’t be! There’s help!”
After asking the Realtime Soft team about Windows 7 support, I received the following answer:
Disabling the window buttons in the registry will allow you to use UltraMon, to do this run regedit.exe, go to 'HKEY_CURRENT_USER\Software\Realtime Soft\UltraMon\<version>\Window Buttons', then change the value of 'Maximize to Desktop Button' and 'Move Window Button' from one to zero.
Big thanks to Christian Studer for this great tip!