I got it. Thanks. Finally found a Google post that works
(
http://social.msdn.microsoft.com/Forums/en-US/accessdev/thread/6007cd79-d17b-42d3-8c51-57c775bd3371/
Scroll to the last reply for the correct code).
I guess I also had to use .End (time) and format the date-times.
My version:
Dim olApp As Outlook.Application
Dim objCategory As Outlook.Category
Dim olNS As Outlook.NameSpace
Dim olApptItem As Outlook.AppointmentItem
Dim olCalFolder As Outlook.MAPIFolder
Dim strOLSubject As String
Dim strOLStartDateTime As String
Dim strOLEndDateTime As String
Dim strFind As String
.Start = Me.txtFollowUpDate + 1 + Me.txtStartTime
strOLStartDateTime = .Start
.End = Me.txtFollowUpDate + 1 + Me.txtEndTime
strOLEndDateTime = .End
strOLSubject = strOLSubject + " " + Trim(Me.txtCorrespondence_Type)
strFind = "[Start] = '" & Format(strOLStartDateTime, "ddddd h:nn
AMPM") & _
"' And [End] = '" & Format(strOLEndDateTime, "ddddd h:nn
AMPM") & "' " & _
" And [Subject] = '" & strOLSubject & "'"
Set olApptItem = olCalFolder.Items.Find(strFind)
If Not TypeName(olApptItem) = "Nothing" Then 'Match found
'messagebox to alert user that OL appt already exists.
End If
-paulw