Red Hat / Fedora :: Cron Job - Rights To Execute Script

I cannot debug or resolve on a Fedora Core 8 machine. The problem exists in a Fedora 11 machine as well. I have a script that changes the default gw (I have 2 providers) if the link is down. The script runs very well when I call it from the terminal, however when I try to set a cron job to run it, it hangs in the middle of the script. I don't have any idea of what is happening, or how to debug but it seems to hang when running a command like: route add default gw [ip]

I can publish the script here, but it's fair an simple and the algorithm is:
- start
- Find out the current GW
- Find out the alternative GW
- Ping the current GW and capture the result
- if we have a fail then change the default gw to the alternative Gw and send an email, else do nothing
- end

The cron job is run as root, so I don't think this is a rights problem.