I Used your ThemeColorizer sample application.
To recreate the problem:
1) Add WM_TIMER/OnTimer to CChildForm
In the OnTimer function add the line AfxGetMainWnd()->PostMessage(WM_COMMAND, INCOMING_MSG, 0)
INCOMING_MSG is a user defined message (place a #define INCOMING_MSG WM_USER+100 in MainFrm.h)
2) Add OnCreate to CCHilldFormView
In this function do SetTimer(IDC_TIMER_CAPTION_UPDATE, 1000, NULL) , add #define IDC_TIMER_CAPTION_UPDATE to resource.h with some value.
3) add void OnCaptionMsg() to CMainFrame, the function doesn’t need to do anything,
a blanc void function will do.
With this setup, run the app and expand any menu in MainFrame.