"File not Found" error
 

What does the "File Not Found" error mean when you are uploading the file? I mean, you HAVE the file. And usually it downloads to as much as 70%, and then you get a "File Not Found" error. What does that mean when you're uploading? I should also note that most of my uploads are successful, but I wonder why these ones aren't, and if I can fix them, so all my uls are successful.

LW 2.9.11. Mas OS X.2.6. DP 1.25 Ghz G4. Cable modem. I'm on a router, should that matter.