ClipShare Video uploading function

I have an installation of [login to view URL] that does not allow uploading large files. It will take a 1-5MB file fine and upload, convert (using Mencoder), and create thumbnail BUT for example, a 5 minute movie that is 50MB in size, it will upload it fine, but will not convert the whole movie. From that I can see, it is when Mencoder is converting the file that it stops partly through the video conversion. It will go and create up to 4-7MB of video, then stop. It seems to stall out and not finish the converting nor will it create the thumbnail. I need this uploading function to work 100% The site is located on a server with specs: WHM 11.23.2 cPanel 11.23.6-R26881 CENTOS Enterprise 5 i686 on standard - WHM X v3.1.0