This thread is long, and I couldn't find a "fix" for the issues with "ToggleStart", so sorry if a solution has been posted previously.
A quick MortScript I am using to get around the issues of the task bar being needed by windows, and also the task bar appearing again when you go to landscape; note I am using SPBShell.
dw = FindWindow( "DeskTop", COMPLETE)
While( 1 = 1 )
If ( WndTop( dw ) < 10 )
TaskBarHidden = 1
TaskBarHidden = 0
s = WindowProcess( ActiveWindow() )
Switch( s )
Case( "MobileShell.exe", "shell32.exe" )
HideTaskBar = 1
HideTaskBar = 0
If ( TaskBarHidden <> HideTaskBar )
Run( "\Windows\StartUp\ToggleStart.lnk" )
I check every 1000ms, which is responsive enough for me, and appears to take up about 1.2% CPU. Problem is that it runs in the background the whole time, but a small price to pay for Full Screen SPB.