MSAccess: FTP File Hanging Open? - ms-access

Question

I am seeing a new oddity in an FTP module I've used for a few years.
Task:
Export an Access Table as XLS
FTP the XLS to my FTP site
Launch a Stored Procedure to insert the XLS into a SQL table
Delete FTP file
Issue: Recently the SP is returning a "0" (fail) when the function is run within quick succession (i.e., within 1-2 seconds). My DBA reports the error as "7303" which seems to suggest the SP cannot grab the XLS file as it is locked OPEN (?)
If I put an arbitrary WAIT of like 5 seconds after the FTP complete before the SP is run, seems to be OK.
Question: Is there any way to force the file to be unlocked/closed sooner?
Here's the FTP function (not mine):
Sub myFTP(Filename As String)
Dim INet As Long
Dim INetConn As Long
Dim hostFile As String
Dim localFile As String
Dim Password As String
Dim RetVal As Long
Dim serverName As String
Dim Success As Long
Dim Username As String
Dim strPath As String
Dim strMsg As String
Dim intReply As Integer
Const BINARY_TRANSFER = 2
serverName = "<my ftp address>"
Username = "<my username>"
Password = "<my password>"
strPath = Left(CurrentDb.NAME, InStrRev(CurrentDb.NAME, "\"))
localFile = strPath & Filename
hostFile = Mid(Filename, 1, Len(Filename) - 4) + "upload"
RetVal = False
INet = InternetOpen("MyFTP Control", 1&, vbNullString, vbNullString, 0&)
If INet > 0 Then
INetConn = InternetConnect(INet, serverName, 0&, Username, Password, 1&, 0&, 0&)
If INetConn > 0 Then
Success = FtpPutFile(INetConn, localFile, hostFile, BINARY_TRANSFER, 0&)
RetVal = InternetCloseHandle(INetConn)
End If
RetVal = InternetCloseHandle(INet)
End If
If Success <> 0 Then
'msgbox "FTP Upload Completed"
Else
MsgBox "FTP function failed"
End If
err_Handler_Exit:
Exit Sub
err_Handler:
errMessage Err.Number, Err.Description
Status "[FTP] - There was an FTP error - process stopped.", "Orange"
Resume err_Handler_Exit
End Sub