I have underestimated upload file size limits but cannot find any file that references file sizes other than filename_dml.php which has no effect when altered. Any suggestions?

PS - the files in question are mp3's and cannot easily be 'reduced' without significant loss of quality

Open the tablename_dml.php file for this table in notepad or wordpad.
You should see the file size you specified in phpmagic 3 places. Make your edits save and re-upload.

Thanks xacto
Had found two of them but didn't go far enough down the page - thanks again