When I open vCalendar, everything looks OK (screen shot 1). Then I click to expand the display which begins a series of issues.
Issue 1: display start time remains at 08:00; but a number of hours are repeated at the bottom (screen shot 2). Note that timezone is OK for items with specific start/stop times; but timezone is not respected for full-day items.
Issue 2: if I open Preferences (over the calendar), or another window, or slide one over the calendar, the lower part of the display blanks. This is probably what vCalendar should look like instead of the repeated entries in Issue 1 above.
Issue 3: scrolling calendar shows entire day (00-23) which looks better, except for timezone issue on full-day items.
Created attachment 1128 [details]
initial vCalendar display
Created attachment 1129 [details]
duplicate entries and wrong timezone
Created attachment 1130 [details]
Created attachment 1131 [details]
scrolled looks better except for timezone
Created attachment 1189 [details]
"valgrind claws-mail", Config.... to blank Name list, closed windows & quit. Nothing else done.
Argh... valgrind output posted to wrong bug... (up all night)
Duplicate of bug 1769?
This seems to be resolved. Saw another bug's update (can't find it at the moment) that looked similar. Closing as resolved sometime before 3.9.3git81.