Irregular behavior of repeats during playback

In pieces with multiple Sections of repeats (with first and second endings), a few of my arrangements exhibit the following behavior during playback:
The first repeated section plays back just fine from beginning to first ending, repeat then to 2nd ending - no problem.
The second (and subsequent repeated sections behave as follows: the first time through the section, up to and into the first ending is fine; the section then repeats as it should. However, rather than jumping OVER the first ending, the playback goes into the first ending (usually only one or 2 measures), and then straightaway into the 2nd ending. Looking at the properties of the measures with Inspector provides no information - the offending first ending measures look just like the ones that work fine. What's even more baffling is that only a few arrangements manifest this quirk. I even tried building a new score, then copying from the old score into it - the "bug" came along with the copy.
It doesn't seem to matter whether there is one measure or more than one in the first ending.
Thanks for any insights - let me know if others have seen this problem.
Ron