Downloads not working

I've got a bloody headache. I've spent all day trying to figure out my php5.ini to allow large uploads, now when I click on the download button I get an error:

File not found

Firefox can't find the file at http://dnbcentral.com/mod/file/download.php?file_guid=33

And when I go to play the mp3 file I get the error: file not found.

Any ideas. Argh. I've checked my data file and its all there.

 

Oh yeah, site is at http://dnbcentral.com