I've used a bit rate calculator to find the proper rate so when Orender my video it will fit on a dvd, but for some reason it won't let me change it in the render as options. when i'm in the options i go to custom, and try changing the system bit rate but it keeps changing it to the value that was already in there. am i trying to change the wrong variable, or is there somewhere else that i change the bit rate?

Are you saving the template after the changes have been made ?

Paul.

whenever i click off the tab for the system bit rate it goes back to the original number that was there before

Don't change in SYSTEMS -after setting up the clips and you're ready to go goto FILE>RENDER AS>(choose MPG2)>CUSTOM>VIDEO>then set you're bitrates and save as (name it here and use the disc icon to save)
The preset will be there until you delete it.

Don