upload through ressources browser

I noticed that I cannot upload a pdf or an mp3 through the ressources browser, strangely i can upload a .doc file however. what can cause this other than the obvious things i checked and were set-up correctly like:

- allowed file types includes mp3 and pdf
- max file size is more than high enough for the testfiles i try
- user settings for these are blank so can’t override site configuration
- permission for assets/files is 777

For this site I am using MODx 0.9.5 and the tinymce/fck ressource browser released with it.

Any help would be very much appreciated!

EDIT:
- also checked diskspace is more than enough
- error message is : failed to upload file - internal error

Check the overrides for the specific user(s).

well like i said:
- user settings for these are blank so can’t override site configuration

’these’ meaning allowed file types and max filesize

They may be blank, but is the checkbox next to each line checked (the one that tells them to use the system config setting)?

If it’s not checked, it’s effectively telling the system that there are no allowed file extensions and thus no files should be uploadable (emphasis on _should_).