Events won't show in May/June/July

Hi all,

I'm using Joomla 3.4.3 (German language) & JEvents v3.4.0RC5 Stable.

Events created in May or June or July won't show in the year's list. Events in April or Sept. do show! (pls see attachment)

If I duplicate an April event it will show in April. If I change the dates of the doubled event to May...it won't show. <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: -->

If i prolongue the time to the next month, e.g. 01. April - 01. May - event will show. <!-- s:?: --><img src="{SMILIES_PATH}/icon_question.gif" alt=":?:" title="Question" /><!-- s:?: -->

I'm confused. Any ideas?

Thanks for all your help.