Using DVD subtitles on a Blu-ray is a really tricky thing, as the size and position information of the DVD subs just don't match at all anymore.
Maybe we can try to improve this in the future, but I'm afraid there is no quick fix for this.
I assume your Blu-ray just didn't have the language subs you wanted?
You could try a resource like http://www.opensubtitles.org/ or http://subscene.com/ to try to find text subtitles for the series in your language, which should work even for a Blu-ray version.
Aye, it's the Japanese blu-ray
release of
Last Exile, for which there is no international equivalent. It contains the English, German, and Japanese audio tracks, and I tend to prefer the latter. However, there are no subtitles--not even Japanese subs.
Finding no acceptable alternative, either in fansubs, or in subtitles uploaded to the sites you linked (not a bad suggestion, though, thank you
), I did end up beginning the process of OCR'ing the subs from the US DVD release that I bought a long time ago; editing, correcting (grammar and punctuation, &c.), and exporting them back into (much more visually appealing) SUP files via Subtitle Edit; and muxing them into the M2TS stream via tsMuxeR. It's a long process, and I'm only two episodes in, but I guess I can appreciate it as a learning experience.
All of that in mind, I guess this is solved for my purposes; however, I would still like to suggest that this be looked in to, since simply ripping the IDX/SUB files and using them as sidecars would be far easier and more convenient.
Thank you for the help though!