I replaced the
case SWFUpload.QUEUE_ERROR.FILE_EXCEEDS_SIZE_LIMIT:
this.queueData.errorMsg += '\nThe file "' + file.name + '" is not an accepted file type (' + settings.fileTypeDesc + ').';
with this
case SWFUpload.QUEUE_ERROR.INVALID_FILETYPE:
this.queueData.errorMsg += '\nThe file "' + file.name + '" is not an accepted file type (' + settings.fileTypeDesc + ').';
and the problem solved.
This is a bug in jquery.uploadify.js