mp3 upload problem

[MikePritchard]

Under the files tab it says:
Max file size: 24MB

but the server is set at:
upload_max_filesize: 48M
post_max_size: 64M
(all php details for server are here: http://pritchardwebsites.net/phpinfo.php)

But I can't upload a 17mb mp3 file. I can upload a smaller mp3 file.
I adjusted some settings in jquery.uploadify.js, I set the timeout to 440 and it will still error out.

So I turned it off and am trying the html uploader.

It still won't upload the 17mb mp3 file. Now after 3 minutes it refreshes the page with no error.

I read all the forum posts on this problem I could find.
I added the below to my htaccess file:
<IfModule mod_security.c>
# Turn the filtering engine On or Off
SecFilterEngine Off
</IfModule>
<Ifmodule mod_php5.c>
SecFilterEngine "off"
SecFilterScanPOST "off"
</Ifmodule>

I sure would appreciate some help on this.
Thanks in advance.
Mike