I'm trying to upload some files that are about 60mb in size, but after a very long time spent uploading through the CRM, I am prompted by firefox to either save or open 'index.php'

The upload doesn't complete, and the page doesn't change from the create new document screen. I've checked the cache folder and there is nothing new in there also.

My upload limit sizes are all in order, through admin and server side and small files work fine.

Any ideas?