When -- is showed on a button , this is because the requested time is not possible.
When using eg. B10 , the event is snoozed until 10 minutes before the ORIGINAL EVENT start time.
So , if i have a event starting at 10.00 with a reminder set 1 hour before..the B10 will snooze till 9.50.
But when that snooze reminder pops up at 9.50 the B10 buttun will show --
This is correct because B10 would mean , snooze till 9.50 , and it already is 9.50.
Same goes if i set a event at 10.00 with a reminder 5 minutes before.. it is just not possible to snooze till 9.50 anymore.