The much better 16:10 resolutions too. Only problem with Multihead I found is with 'Center popups at screen..' and WinOS2. The WinOS2 popups are not moved to the center of on monitor and are not fully drawn too. Then you can not click on the partly drawn buttons and only kill this WinOS2 program with f.i. xcenter. So have to disable 'Center...' before starting WinOS2 and reenable afterwards.
Does WinOS2 work with Multihead and 'Center...' for anyone else?
EDIT: I am discussing my experiences with WinOS2 Seamless on multihead - NOT my experiences with WinOS2 Full Screen. I cannot (easily) test my WinOS2 Full Screen experiences since I (virtually on day one) installed WPS4Win.
WinOS2 works fine here (ATI Radeon 9250 and SNAP full version, post SMP fix (don't know the build level, but I can check if necessary). Since in reality, they are really redrawn (drawn over) OS/2 folders/dialogs, it is weird that they would not work properly. Even their specific folder properties are derived from OS/2's default folder properties (border width, border colors, etc).
I have seen the drawing corruption you speak of, but that is usually because of a graphics or system component that is at a level mismatch for other components that are installed (or a video card driver issue). It usually happens in a failure during the "draw an OS/2 dialog... now paint a Windows-like dialog over it" stage.
I'm running multihead (2 LCDs) at 1280x1024 each, side by side orientation. My WinOS2 session is locked to the first head, and full screen (as expected) spans both heads. Un-maximizing restores the stored position on the first head (in the same fashion it would for any other OS/2 dialog box).
The only other time I've seen the redraw issue is on certain software on earlier versions of OS/2 (such as Warp 3... or possibly OS/2 2.1, and programs such as QuarkXpress 3.1, where it uses a toolbar with custom sized "sysmenu" and titlebar controls, and OS/2 doesn't properly scale the OS/2 equivalent, and then follows up with improper drawing of the Windows-like controls over it - but that was resolved a long time ago.