I can not upload anything larger than 5M. I have the configuration set for 20M for frontend users, but I can't even do more than 5M in the back end either. It keeps coming back with a response of "Invalid Token". We love the features of this and want it to work, but need to be able to upload large file sizes for storage. Joomla 1.5 under global configuration, Server, Media Settings I've set it for Maximum byte size: 15728640. I'm lost as to where else to look to fix this situation. I've searched the net for an answer and can't find one. Can any one help me out with this problem.
Thanks!

The solution is located in /etc/php/php.ini
Allowed file uploads: should be YES
Maximum allowed filesize (max_filesize): for you is 5MB, ask your administrator to change it to higher if the system and hosting plan allows it
Maximum allowed POST size: (post_max_size): for you is unknown, but it should be double by allowed filesize:

Memory limit (memory_limit): if filesize is 8, POST is 16, this should be 32MB

Maximum input time for uploads (max_input_time): if the server is in your local network, or your ping to it is lower then 30ms, 600 value is ok, if you're over 6 hops to your server and between 80-100 or over time in ms, this option should be higher.

All this and more can be founded on www.php.net