Toast burn 5 hour dvds?

When i author DVDs in idvd the application quickly realizes if a movie is too long and exceeds size limits. This usally ends with all my dvds with a running length of ruffly 2 hours. On Toast this is the same case, except for 2 DVDs which had multiple clips that add to almost 5 hours of video. Is their really 2 hour cap on dvds, or does it only matter the size of the files. Could it be also that the encoder really compresses the video files and I end up losing a lot of quality? I cant tell, ive only been burning cartoon series. THanks

A single layer dvd will only hold roughly 4.4 GB of data, regardless of what it is. That should be the only limitation.
If you have 5 hours of video that comes in at less than that, you should be able to get it onto one DVD.