Regarding the small difference in BLEU scores on MT08, we would like to point out that tuning on MT05 and testing on MT08 had a rather adverse effect with respect to translation length: while the two systems are relatively close in terms of BLEU scores (24.83 and 24.91, respectively), the dependency LM provides a much bigger gain when evaluated with BLEU precision (27.73 vs. 28.79), i.e., by ignoring the brevity penalty.
the difference on MT08 is significant in terms of TER.