[WIN32SS] Regression Pocket Tanks 1.6 does not properly switch the desktop resolution before entering fullscreen

0.4.10-RC-30-g51a70dc gcc dbg lin, VBox 4.3.12 with VBEMP
Pocket Tanks 1.6 from rapps.

When having the desktop resolution set to 800x600 in ros the game does properly run in fullscreen and the games content covers the full screen.

But when having the desktop resolution set to 1024x768 in ros the game does still want to draw in fullscreen, but draws only within the 800x600 area, leaving the desktop visible in the outside area. This is because ros does not automatically switch into 800x600 before (Games content is hardcoded to be limited to 800x600)
0.4.10-RC-30-g51a70dc__1024x768.png
0.4.10-RC-30-g51a70dc__1024x768.log

Contrary WinXPSP3 does actively switch from 1024x768 to 800x600 when the game is started. xpsp3_automaticallySwitches.png and therefore fills the whole screen even then.

This is a ros regression
The bug appears as described in here in 0.4.5rls, 0.4.6rls, 0.4.7rls, 0.4.8rls, 0.4.9rls, 0.4.10-RC-30-g51a70dc.
But I noted in 0.4.4RC1rls-test: "fullscreen working perfectly now when started from desktop 800x600 & 1024x768 (no taskbar visible ok)"