This worked for me with 2.5 –
Check if you have the ‘uploads’ folder in
wp-content, create it manually if not.
Set permissions on the folder to 777.
Add this to your htaccess file –
<IfModule mod_security.c>
<Files async-upload.php>
SecFilterEngine Off
SecFilterScanPOST Off
</Files>
</IfModule>
Your done! 😉
hth
