Constant out of memory errors

Question

I am consantly receiving out of memory errors in fcp 5.1. Now when rendering I have to split it up into sections to render so I dont get the error (eg - render 5 seconds of footage at a time)
My rendered files folder contains 203 files and I was wondering whether I could just delete all the files and then just re-render the project in one go - or will this just screw up the project?

Answer 1

If I delete all the rendered files, when I re-render will it make just the one render file? If so does this mean everytime I make a change in the project it will take longer to render as Final Cut will have to re-render the whole file?