Cant copy from dvd-r to dvd+r

I cannot make a copy of a video compilation from a dvd-r to a dvd+r. I have used:

4 different dvd writers
2 different computers (XP and XP Pro)
2 different software programs (nero and sonic)
2 different brands of dvd+r (memorex and HP)
tried burning straight from video editing program

Nothing has worked so far

Please help!!!

:a

A dvd -R holds very slightly more than a dvd +R. It is usually not enough to matter—4.384gb vs 4.378

Is this video compilation in dvd-video format? In other words, can it play on a stand alone player just like a commercially made dvd? If so, you can use DVDShrink to rip to the hard drive as an ISO, (let it compress the video very slightly if the program says it needs some), and then burn to a disk with whichever program you prefer. For burning ISO’s of dvd video, ImgBurn works very well, and is free.

If you don’t already have it, DVDShrink can be found at www.mrbass.org Look at his guides on using it.

If your compilation is just a collection of files, rather than a dvd-video, you may have to reduce the size slightly, if you are over the limit for a dvd +R.