Henrik,

what browser are you using
maybe you can email the file to me and i'll try uploading that same file in using the same browser

OR

try a different file and different browser

There was an issue, but its fixed and the issue was not related to browser or browser cache etc, it was related to the fact that i'd forgotten to create a temporary directory for the uploaded files. Since has been corrected, the upload process works.

Though i have to say, the issue was never something that should be affected by what you're doing at your end.