The inconsistency caused uops mode to fail on an older version of libpfm since the dispatched_port was added as an alias for executed_port only after v4.6.0 of libpfm.
That is weird. If I understand the intel doc correctly, both these names refer to the same event (EventSel=A1H, UMask=01H). I have a haswell machine and dispatched worked (but I patched your change and I get the exact same results, which is to be expected given that the event is the same). What version of libpfm do you have ? I've seen both work on`4.10.1+git14-g815ff28-1`.