Birthdays shown twice in events view

REPRODUCIBILITY (% or how often): Always
BUILD ID = OS VERSION (Settings > About product): 4.2.0.21
HARDWARE (XA2, X10, X10 II, …): XA2
UI LANGUAGE: English
REGRESSION: (compared to previous public release: Yes, No, ?): ?

DESCRIPTION:

Birthday reminders are shown twice in the events view.

STEPS TO REPRODUCE:

  1. Add contact with birthday in people app
  2. Approaching the birthday 2 reminders are shown in events view
  3. Both reminders display different details

EXPECTED RESULT:

To have a single events view reminder for a birthday

ACTUAL RESULT:

2 Reminders for the same birthday are show. Each reminder is set-up differently in displaying data.