Drive Error

How come I get this when my DVD is done burning?

"The drive reported an error:
Sense key = MEDIUM ERROR
Sense code = 0x73, 0x03"

This JUST started happening. Ive tried burning it twice and both times i got the error. My file is an .avi file and is around 700MB which should be fine. Im using FujiFilm DVD+R and am burning at the lowest speed possible. I think these DVDs are sketchy. I used Msonic DVD-R before and they worked perfectly. These +R DVDs have a tendancy to work sometimes and not work at all other times. Also Im using Toast Titanium 7 but i dont think that has anything to do with it.

Help please?