WEBUTIL (attach and view files from database) --- Vista vs. XP differences

Question

I have attached the following code. We are using Oracle Application Server 10.1.2.3 patch
My questions are provided following the code.
-- Open the local temporary file --
-- v_COMMAND := 'cmd /c start "" /WAIT "' || v_FULL_FILENAME || '" /w';
v_COMMAND := 'cmd /c start "" /WAIT "' || v_FULL_FILENAME || '"';
v_PROCESS_ID := WEBUTIL_HOST.blocking( v_COMMAND );
v_TEMP := WEBUTIL_HOST.GET_RETURN_CODE( v_PROCESS_ID );
If v_TEMP <> 0 Then
r_ERR_MSG := 'Host command error(' || To_Char( v_TEMP ) || ')';
v_FLAG := WEBUTIL_FILE.DELETE_FILE( v_FULL_FILENAME ) ;
RAISE PANIC;
End if ;
if p_FILE_ACCESS = 'W' then
-- Re-store the modified file in the database --
If Not Webutil_File_Transfer.Client_To_DB ( v_FULL_FILENAME, 'mis_mst.FT_SUP_FILES', 'FILE_DATA',
'FILE_NBR = ' || To_Char( p_FILE_NBR ) ) Then
r_ERR_MSG := 'Error on storing file';
Raise PANIC;
Else
Clear_Message;
-- show_message('File re-stored in the database') ;
End if;
else
Clear_Message;
-- show_message('NOTE: "' || v_FILENAME || '" was not updated in the database' );
end if;
-- Remove the temporary local file --
v_FLAG := WEBUTIL_FILE.DELETE_FILE( v_FULL_FILENAME ) ;
If v_FLAG = FALSE Then
Bell ;
-- show_message( 'Error removing "' || v_FULL_FILENAME || '" from the PC.' );
End if ;
For the most part, we are able to open files in both XP and Vista. We are having a couple of problems with certain file types; specifically, (JPG and ZIP).
We have a workaround, but I would like to know why the problem occurs.
When the user opens a JPG from our application using the Windows Vista client (JPG are associated with Windows Media Player by default), the system will not open the file. The system states that the file doesn't exist. What I think is happening is that Windows Media Player takes awhile to load and before WMP is fully loaded, the file is deleted (the /WAIT command must not fully wait for the command to complete, causing Forms to continue with its code to delete the file). When WMP tries to open the file, the file has already been deleted from the operating system. I have tried the "/WAIT <filename>" and the "/WAIT <filename> /w" parameters.
The workaround is to reassociate the file with MS Paint or Microsoft Office Viewer (instead of Windows Media Player).
Are any of you aware of issues (or differences) in the wait command between Windows XP and Windows Vista?

Answer 1

Thank you, Thank you, Thank you!!!!
I believe that will work (adding a sequence number to the end of the filename)!
We do not allow a user to update the file, only view. If a user wants to make a change, they need to remove the existing file (from the database), create a new file (outside of our application), and attach the file in our application (into the database). All updates occur outside of our application - we are not a document authoring system, just a document storage system.
Once again, many thanks on the solution!
Mike