Hi,
first i have to apologize – it was late in the night and i got almost crazy….

Well, it was not a caching issue (i deleted it several times).
And i use the impleted LayerSlider (no standalone version).

Finally: i upgraded to version 3.2. and re-created all pages manually.
Took some time – but it’s stable now.

I use it on Debian 8 / Jessy with Apache 2.4 and WordPress 4.2.2.

Unfortunately, i could not wait for your help – website had to be up asap.
And I did not expect to get answers as fast as it happened finally.

Again my apologies: your theme is great! It was just the issue with LayerSlider WP.

Best regards
Joerg