[CentOS] PHP file upload limit

Hi all,

I am trying to run a web-based PHP application on a CentOS 5 32-bit
machine that requires me to upload large files. The machine also
happens to have little RAM (256MB).

I have no problem setting my upload limit ( upload_max_filesize ) to 1
GB but for some reason 2 GB or above seems to be no go. Would anybody
know why? Could it be one of the many 32-bit vs 64-bit issues?

Thanks.

Boris.