The syntax for opening a form is:
DoCmd.OpenForm formname[, view][, filtername][, wherecondition][, datamode][, windowmode][, openargs]
with the "windowmode" section being the determiner of how the form opens. I suspect you've either got yours set to acWindowNormal, which is how it's opening, or you've left this arguement blank, in which case it defaults to acWindowNormal.
You need to substitue the arguement acFormDS to get it to open in DataSheetview.
Hope this helps!
The problem with making anything foolproof...is that fools are so darn ingenious!
All posts/responses based on Access 2003/2007