Hi Jan
I actually have the same problem

And yes it is extremely frustrating,
if you try to upload a picture called "mercedes170.jpg"
chances are that it will be already on the server.
however.....
what I have started to do is change the file name to today's date.....eg....
"12_04_2010_mercedes170.jpg"
this way, you can be sure that there will not be a file on the server with that name already,
I understand it is frustrating, it has happened to me countless times
Some forum software when they upload a file, they change the file-name to a random name, unfortunately ours does not do this.