Alex,
Just an idea. Novel 4.11 you say. As I remember from my Novell days, novell was using signalling packets called watchdog packets to determine if a station is dead. If it considers it's dead was disconnecting automatically. I'm not sure if this really applies. If failures are happening after certain duration of time then might be. Logging on you 'awake' the connection and it succeeds? If it's the reason then probably at periodic intervals writing a small file follwed by erasing it might cure the problem (but might lead to another problem of Novell I remember - files not purged cause a contention and bring Novell to a halt).
Cetin

>Hi,
>
>I'm having a crazy error happening randomly:
> System.IO.FileNotFoundException: Could not find file "f:\Case.dbf".
>
>F: is a drive in a novell 4.11 server.
>E: is a drive in the local machine (where this code is running).
>
>Here's the code:

Try
>     File.Copy("f:\case.dbf", "e:\GeneralDropFolder\case.dbf", True)
> Catch ex As Exception
>     'There was a problem copying the file.
>     CopySuccessful = False
>     'Add entry of this event to log.
>     Echo("Attempt to copy file f:\case.dbf to e:\GeneralDropFolder failed." _
>         + Chr(13) + Chr(10) + "Additional error information: " _
>         + Chr(13) + Chr(10) + ex.tostring(), False, True)
> End Try

Here's the output from the log:

2005-11-28 22:01:56 Attempt to copy file f:\Case.dbf to E:\GeneralDropFolder failed.
>Additional error information:
>System.IO.FileNotFoundException: Could not find file "f:\Case.dbf".
>File name: "f:\Case.dbf"
>   at System.IO.__Error.WinIOError(Int32 errorCode, String str)
>   at System.IO.File.InternalCopy(String sourceFileName, String destFileName, Boolean overwrite)
>   at FTPDirect.Module1.Main()

Right after the program aborts, I go to the computer, try to access the F: drive and everything is there (F:, F:\case.dbf, etc.). It shouldn't have failed.
>
>Anybody has any ideas of what could be causing this? Or at least how to track the damn thing down?
>
>I've added code to have the program wait 10 minutes and attempt 2 more times (at 10 min intervals) and all the attempts fail.
>
>After I log onto the machine and try to access the file that wasn't found, I have no problems.
>
>I then re-run the program that does the copying and that works as well.
>
>We're pretty desperate.
>
>Thanks for your help!!!!
>
>Alex