probems creating folders: "......... folders already existed"

Hello everyone. I am trying to add onto to some code that I developed some time ago. The user is promtped from a mesage box to enter a date, that then passes through the variable called fDate. I then create a series of folders based on fDate. For example if the user enters the date of 30-jun-2010 a folder called 30-jun-2010_157 is created. What i would like to do is also create folders for the two months prior to fDate, that would be 30-apr-2010_157 and 31-may-2010_157 using June as an example. And so I coded that in however when I run the code the "computer" tells me that the two previous months to this date through "already existed". I suspect the problems lies in my use of the variable ErrBuf ?

  Dim fDate          As String
    Dim fPath            As String
    Dim fDatePrevious1   As String
    Dim fDatePrevious2   As String
    Dim fDatePrevious3   As String
    Dim fPriorDate1      As String
    Dim fPriorDate2      As String
    Dim fPriorDate3      As String
    
    Sub CreateFolder()
'***********************************************************************
'CreateFolder() macro creates the folders for the 157 Automation process.
'***********************************************************************

    Dim Fldr   As String
    Dim ErrBuf As String

    fDate = Application.InputBox("Enter a date in the format shown:", "Date to add...", Format(Date, "DD-MMM-YYYY"))
    If fDate = "False" Then Exit Sub
    
    fDatePrevious1 = DateSerial(Year(fDate), Month(fDate), 0)
    fPriorDate1 = Format(fDatePrevious1, "DD-MMM-YYYY")
    
    fDatePrevious2 = DateSerial(Year(fDate), Month(fDate) - 1, 0)
    fPriorDate2 = Format(fDatePrevious2, "DD-MMM-YYYY")
    
    fDatePrevious3 = DateSerial(Year(fDate), Month(fDate) - 2, 0)
    fPriorDate3 = Format(fDatePrevious3, "DD-MMM-YYYY")
       
    '**********************************************************************
    'Formula used to calculate the prior quarter.
    '**********************************************************************

    fPath = "L:\"

    On Error GoTo ErrorHandler
        
        Fldr = fPath & fDate & "_157"
        MkDir Fldr
        
        Fldr = fPath & fDatePrevious1 & "_157"
        MkDir Fldr
        
        Fldr = fPath & fDatePrevious2 & "_157"
        MkDir Fldr
        
            
    If Len(ErrBuf) > 0 Then MsgBox "The following folders already existed:" & vbLf & vbLf & ErrBuf
    
    Exit Sub
    
ErrorHandler:
    ErrBuf = ErrBuf & vbLf & Fldr
    Resume Next
    
End Sub