This is the first time I have encountered this problem, which I suspect may be a DVD player bug. I am looking to see if anyone else has ever run into this behavior.
I exported regions as subtitles from Vegas (v9) and created a DVD with these subtitles using DVD Architect v5.0.
On one player (the Sony BDP-S370, a Blu-Ray player in Sony's current product line), the end of a subtitle is not being detected and hence a subtitle only stops
displaying when another subtitle is encountered. The subtitle momentarily blinks at the point it is expected to end, but continues displaying.