TypicalSurfer - 3:04 pm on Aug 10, 2012 (gmt 0)
"The OP's path to php was /usr/bin/php, should not be needed to export anything."
I recently encountered the same issue and found that cron passes a minimal or even a wrong set of environment variables to jobs.
If you can run the sript from a command line but it fails to run with cron, you have to set environment.
export PATH=/whatever/your/path/is ("env" PATH output)