The different DVD sizes is interesting, I use TDK discs and as far as I know all TDK DVD's are made in Taiwan therefore they should be the same size everywhere regardless of which country you are in.
According to Nero TDK discs can take up to 4488MB (OR 4,706,074,624 bytes when viewing DVD Properties in Windows).
I dont currently have another brand DVD available to see if it is just the TDK which allow 4488MB. I have always just considered DVD's to allow 4480MB and have never had a reason to check a DVD's exact size until I seen both your posts.
