Can't set paper size less then 4 inch

Hello guy's

I have trouble to set paper size crystal report from vb 6 coding, this is my coding :

Private crApp As New CRAXDRT.application
Private crRpt As New CRAXDRT.report

Set crRpt = crApp.OpenReport(App.Path & "\rekening_baru.rpt")
crRpt.PaperOrientation = crPortrait
crRpt.SetUserPaperSize 3.67 * 254, 9.5 * 254
crRpt.PrintOut False

if the script run, then output size height is not 3.67 inch. But if height value replace with >= 4 inch, is work normally.

Please help me to find best solution.

Thanks before