Isn't the whole point to flash that it is scalable to any resolution?

Only if it is all vector art. Any pixel based asset will distort in some manner if resized.

That would be my first question then. Is it all vector?

Second..if you are going to use a standard DVD player, the DVD MPEG spec is 720x480. So your video needs to be scaled down by 2 1/3, which will get you 720x450. This means you will have 15 pixels of full black on left and right. You may be able to stretch it to fit without too much of a noticable difference. But remember these are non-square pixels!! Also, convert your colors to CMYK before making the DVD. TV color space is somewhat similar to print. It will not replay RGB red (255,0,0) without significant distortion in the video AND audio!
For best picture quality use component cables between the DVD player and TV. If not, the next best would be S-Video. Last resort, use the composite cables.

Thanks so much 'technical' terry, ive only just graduated and been given this job its an awesome opportunity but still i'm a little over my head with technicalities such as this! as for is it all Vector it is, But i've put the flash film into After Effects to add various effects (lens flare etc.) so it's technically no longer a flash piece?
any idea?

Yeah AE is great for finishing and effects. Make a new composition in AE that is Broadcast NTSC (720x486) or PAL (720x576) whatever it is that you are using. Drag in your previous comp onto the new one. Resize it, using the corner points, to the size you desire. "Make Movie" out of AE, Quicktime format, use the animation codec, ensure you have the correct frame rate and all the jazz. Make your DVD with the resulting Quicktime movie.