birthday duplicates after removing google account and adding it again After removing my Google-Account on my HTC One S and adding it again, i recognized that all birthdays stored with contacts are in my calendar twice. When i change birthday at some contact, there is only one, which changes. The information is not from another calendar like Facebook or Google.
After removing my account once and adding it, i had two birthdays for each contact, only one changes.
After removing my account another time and adding it, i had three birthdays for each conatct and only one changes.

So why this happens or how can i delete or avoid this?

I would like the delete either automically or manually (prefering automatically) but i found no solution to do this.

I made a screenshot to make it clearer.
Meanwhile, the only thing that helped was a softreset.i wanted to do it fast. And after the new HTC Update i switched to some Custom Roms anyway.