Ubuntu 8.04 server is not retaining a static IP address

Ubuntu 8.04 server is not retaining a static IP address

I recently setup a linux box running Ubuntu 8.04 (to match another server with 8.04). I need to insure that this box has a static IP address and I changed /etc/network/interfaces to set up the static IP address and when I run sudo /etc/init.d/networking restart it works fine for a while, but always reverts back to 10.0.1.24 after being idle for a while.