I have encountered an odd situation where the bookmark property doesn't seem to want to behave.
It is important that my user be able to .Requery her subdatasheet and not end up losing her place. No problem:
Code:
Dim strBookmark As String
strBookmark = Me.subOrders.Form.Bookmark
Me.subOrders.Form.Requery
Me.subOrders.Form.Bookmark = strBookmark
and it works - most of the time. Oddly, if you put on a filter of any kind in the Subdatasheet and ran just these 4 lines on a button_click event, you'll get an Invalid Bookmark error. Close the error dialog and try again - everything works just fine. Now toggle the filter off and you'll get the Invalid Bookmark error dialog again. Close it and everything works fine.
Seems like the first Requery after you apply a filter invalidates a previously stored bookmark... at least in this DB, I cannot reproduce it elsewhere.
Have a look if you want. The only button/code you need concern yourself with is the one captioned "Command117", and the Datasheet subform right above it. The "order manager" Form where all this is happening should open automatically.
I've got a workaround, but I feel like I need closure as to why this is happening.