Ok not working on large files

Now the for the second time (this time with blue-ray input of 15G with standard /h.264 baseline/ output 25000 bits (no deinterlace), the file is fine for about the first 1/3rd or so but then becomes unreadable (with Womble Video Wizard dvd), same with quicktime, and powerdvd8 wont even open the file. Output size was 20G.