DTS article on Wikipedia
DTS (also known as Digital Theater Systems), owned by DTS, Inc. (NASDAQ: DTSI), is a multi-channel digital surround sound format used for both commercial/theatrical and consumer grade applications (with significant technical differences between home and commercial/theatrical variants: the latter being a traditional ADPCM compression system and the former a sophisticated hybrid perceptual and signal-redundancy compressor based on ADPCM called APTX-100). It is used for in-movie sound both on film and on DVD, and during the last few years of the format's existence, several Laserdisc releases had DTS soundtracks.
As for blocking, I have to understand this better: it blocks _AFTER_ you select an option? I.e. the screen works, but is blocks after you press enter instead of going to the confirmation screen (last screen). If this is the case, it's possible that it's a libxine issue that was found recently (and, as a rule of thumb - Murphy-style, once an issue is discovered, it starts manifesting itself for everybody, regardless if the systems worked just find up to that point :shock: )