At the bottom of stdafx.h, there are some wizzard generated lines. They begin with:
The line that make the controls "3D":
#pragma comment(linker,"/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='18.104.22.168' processorArchitecture='x86' publicKeyToken='6595b64144ccf1df' language='*'\"")
They contain Windows common controls manifiest.
Remove the first ifdef (unicode) and the last endif.
The common controls manifiest work ok for both unicode and multibyte (at least I had never had a problem).
Hope it helps.