nixCraft posted a quick guide about increasing the PHP upload file limit from 2MB to 10MB under Apache 2 UNIX / Linux
How do I increase upload file limit from 2MB to 10MB under Apache 2 UNIX / Linux web server?PHP Increase Upload File Size Limit
Your php installation putting limits on upload file size. The default will restrict you to a max 2 MB upload file size. You need to set the following two configuration options: