I just wanted to log in to say thanks, Fransisco Teo.
After a couple hours of banging my head against the same error, I tried your method of adjusting the subtitles so that they didn’t touch around where the timecode was noted in the error. I had to do this a few times, but after they were all ironed out, no more errors!
Look at me, I’m excited about burning a DVD in 2015!