FWIW I get the same. A vertical scroll bar that virtually fills the RHS, and does nothing (is not scrollable)
If I double click the title bar to maximize, it fills the screen space correctly. If I then close and reopen, it hides the lower part of the page behind the Windows task bar again.

However, if I simply re-size to a new reposition without maximizing, when I close and reopen, it restores back to the last used position.

I am running 2013 build 366 on Windows 7 Ultimate 64bit. Screen Res is 1920 x 1200 (might be related...)

BIAB & RB2025 Win.(Audiophile), Sonar Platinum, Cakewalk by Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Kontakt, Focusrite 18i20, KetronSD2, NS40M Monitors, Pioneer Active Monitors, AKG K271 Studio H'phones