Lightroom and editing in CS2..multiple files generated

If an image is edited in CS2 Lightrrom creates another file xxxxx_edit2.psd. If the same psd is opened again, it generates xxxxxxxedit3 etc etc ad infinitum!

I find this annoying because Im getting my psd files saved with the prefix edit2-3-4 etc so getting multiple files. Is there a way to disable this, I want to edit the original psd file and resave it, not save another version. I get that it creates a history, but Im more concerned with the disc space