It is not a "known" problem, therefore i don't know what is going on after you enable the JoomSEF.
Just make sure JoomSEF doesn't include anything to your website beside modifying the URL's.
not working zoom effect problem must be caused by the jQuery conflict. Do you have the "Firebug" plugin? Or are you using any kind of development plugin? What your console says? are you seeing some kind of JS Conflict issue?
Make sure JoomSEF
- it doesn't load any jQuery library to your website
- It doesn't load any social media buttons (because eventually there will be some JS files)
- It doesn't use any JS file compression
- It doesn't load any JS file extra
Open the JoomSEF configuration and disable everything that you don't need. By default, it might add many things which probably you won't need them.
You should use JoomSEF only for controlling the SEF URL's and META Tags.. nothing more.
You may create a topic in JoomSEF forum and ask support from them which will make much more sense, because i don't know what structure they are using. For instance i just find this forum thread:
www.artio.net/support-forums/joomsef/community-support/joomsef-4/joomsef-conflict-with-component-parainvite
In that case, the support guy recommends
Try disabling the "Fix index.php links" option in JoomSEF's Configuration on the Advanced tab.
My point is, they put this option in the configuration and only "they" know what that is. Probably a parameter something like that is causing the problem so needs to be disabled and only joomSEF support can help you about it.
Regards.
Support & Development