Yeah my WRC4 copy backed up perfectly. I used Verbatim 16x advanced AZO+ DVD-R fyo, theyre always the best to go for. As for burning, take hessajee's advice too and use DVD Decrypter. I burnied it at 4x as it wont burn at 2x, but try burning at 2x first, and if it works, use that. If you want to try it at 4x just to see if it works.
Also, check what version PS2 you have and what media it best supports, My v3 PS2 works better with DVD-R, generally if you have a higher version PS2 then DVD+R's work bettter (but don't quote me on that completely)