Thanks again. I came a lot further now. I changed themes but no difference. But I use a lightbox plugin named Jquery colorbox, which had already sometime a new version which I don't installed because it pops up my tabs. This version has a newer version of Jquery.
But, if I install the latest version, the WPtouch/Jetpack problem is gone! But I really don't like my tabs popped up, so have to find a workaround for that. Any solutions maybe?
This helps me a lot anyways!