You are right there is a bug !
For single disc and two disc releases we compare every every song with every track and then work out a match that allows every song to be matched to one track and with the best score. (Because the number of possible combinations gets too large we use a different method if release has more than two discs).
But we are comparing song track no with the contiguous track no of the release, the contiguous track no is what the track no would be if we treated the release as a single disc release, so in your example that would be tracks 1-35. This makes no difference for disc 1 but for disc 2 it means that for this release (with 11 tracks on first disc and 25 tracks on second) the first song on disc2 is should match 11th track based on disc no/ track no but instead matches the 1st track and the 11th track on disc 2 should match the 22nd track but matches the 11th track.
Now track no is only one part of the score weighting used to compare each song with each track, but because you essentially have the same song twice on disc 2 with in most cases the same duration and the artist is the same for all tracks there is little to differentiate so in some cases the track no match is causing the wrong mapping to be selected.
What we should match against disc no/track no if songs have disc no/track no or try matching against track no and then contiguous track no if songs only have track no.
An additional problem I noted if if your songs do not have values in the disc no or track no fields then we try and match without this information, but in your case this information can be parsed from the filename so we should try and parse this information.
Raised https://jthink.atlassian.net/browse/JAIKOZ-1410 and should be fixed soon for next release.