Setting checkbox selected

I am trying to set a checkbox selected in a custom page using a pre call. The only checkbox that is selected is the one I used SelectIn on which I alway want on. The function works fine for setting the install type, but the SectionSetFlag is not working at all. What I am doing wrong?


Function ComponentsPre

SetCurInstType 0

; check if a previous custom install was done
; if yes, then set custom install type and enable checkboxes

ClearErrors
IfFileExists "$INSTDIR\c1.win.c1report.2.dll" yescro chkadm

yescro:
SetCurInstType 1
SectionSetFlags ${SEC11} ${SF_SELECTED}

chkadm:
ClearErrors
IfFileExists "$INSTDIR\SEQUEL_Admin.EXE" yesadm chkexcel

yesadm:
SetCurInstType 1

chkexcel:
ClearErrors
IfFileExists "$INSTDIR\SEQUEL.ExcelAddIn.Interface.tlb" 0 end1
SetCurInstType 1
SectionSetFlags ${SEC13} ${SF_SELECTED}

end1:

FunctionEnd

After some debug I found the issue. It is the SetCurInstType that clears the previously set section flag. I moved the checks around and the last one processed alway worked. Then I started commenting out things to see what might be clearing the flag and discovered it was SetCurInstType. I can code around this now that I know it does that. The documentation didn't say anything about it clearing an already set section flag.

Clearly it has to set the section state, that is the only way it can apply a specific install type.