You know, I don't think that the XBMP is capable of reading the IFO stuff like a DVD player or computer hardware does. I have attempted several times with no luck. The moderators of the forum probably know more about the way the reader interprets the files. I just flip through the VOBs until I see the start, then watch it until the end of THAT VOB. Then, you have to start the next succession VOB. Beware about the audio track though......it is common for some VOBs to play a different track....ie french/german etc. You just have to flip back to your language type. Annoying, but OK.
I have recently been using the Gordian Knot as described in other forums with better luck. The sound with a compressed DIVX is WAY SUPERIOR to that of the output from a VOB for some reason. If you look back about a week or so, I posted a question about the XBMP sound quality. In playing VOB's, I get distortion sometimes at the peaks, but with the DIVX crunched track it sounds great.