Norskman,
How big is the file that you are trying to upload. I have tried a few things to get ownCloud to upload files larger than 2 gb but my mileage has varied. I have managed to upload a ~ 11gb file on to an ownCloud instance running on a i3-16gb (see signature) machine but I have not been able to repeat the process with other instances of ownCloud installed on the same machine. I am not sure why. The max I have been able to upload is 4GB and then the upload process stops. In fact you can see the file getting uploaded to the temp directory and then stop at exactly 4GB. I am still trying to figure out why? If you have not changed your setting from the time you installed the plug-in I share my script with you.
To confuse me further I have also managed to upload a 11GB file onto my PCBSD test box having only 5GB of memory! As far as I can tell the config is exactly the same on all instances but I am getting different results.
On another note , we really need to figure out why we are trying to upload such a large file using a web-browser instead of rsync , scp or ftp!! My story is that I am only doing to understand the process and I am sticking to it ;)