Adding wrong code with Insert Gallery Window

We installed NextGen Gallery and have problems in integrating a Gallery into our Posts or Pages.

– WordPress up to date? Yes
– NextGEN up to date? Yes
– What version of NextGEN Gallery did you upgrade from? (i.e. I had 1.9.13, then upgraded to 2.0.61) new installed
– MySQL up to date (at least 5.0)? Yes
– PHP up to date (at least 5.2.4)? Yes
– The mod_rewrite Apache module activated? Our hosting-partner tells us, that WordPress writes this data automatically as soon as we define how the URL of our Gallery should look like.
– PHP Safe Mode OFF? Yes
– What theme are you running? WordPress Adventure

When adding a Gallery into a Post with the Insert Gallery Window it adds the following code:
<img class=”ngg_displayed_gallery mceItem” src=”http://www.gustofrenzy.com/nextgen-attach_to_post/preview/id–1163&#8243; alt=”” />

We can see the preview picture in the editing mode of the post, but as we publish the blogpost we still only can see the preview picture (without any link to other pictures, slideshow or thumbnails whatsoever).
The written code by the Insert Gallery Window seems to be the problem, as the shortcodes one finds on the nextgen-website look quite differently. And if we add the codes suggested on the website manually it all works perfectly. We did not find out how we can resolve this problem. Did we miss anything regarding the URL of the gallery or what could be the problem?

Thank you all very much in advance.

https://ww.wp.xz.cn/plugins/nextgen-gallery/