When CMFCPropertyGridCtrl is in alphabetic mode the vertical scrollbar does not function correctly. Expanded groups which have many sub-items do not increase the scroll size as expected.
Tracing the problem with the debugger it would seem to come from this function in afxpropertygridctrl.cpp:
int CMFCPropertyGridCtrl::GetTotalItems(BOOL bIncludeHidden) const
Inside this function there is separate logic for calculating the item count depending if alphabetic mode is enabled. When alphabetic mode is enabled the following is used:
This doesn't take into account the sub-items. The logic for calculating item count when alphabetic mode is not enabled is as follows:
nCount += pProp->GetExpandedSubItems(bIncludeHidden) + 1;
I believe the latter should be used for the alphabetic mode as well instead of the simple nCount++ which ignores the sub-items.