Uploading new versions of a file
It is possible to overwrite a file with a new version, you do not need to create a copy of the file with a new name. To do that, you can either directly use "Upload file", which will tell you, that a file of that name already exists, or you can go to the page of the file (e.g. Image:PProblems_4.pdf), where you can find a link "Upload a new version of this file".
Now I see that you apparently have tried that. I now guess that you tried downloading the file after you did upload the new version, and that you didn't get the new version. Is it possible that you forgot to reload the page that contained the link after you uploaded the new version?
--Olenz 07:16, 28 November 2007 (CET)