Where do you see "There is an "Activate/Deactivate Auto Reload" feature"? if you're talking about the new icons (Display/Tab > Icons for ...), they simply show if a tab is set to reload. To set reloading you can Rclick a tab and click Reload tab every ... > and set time. Or you can check the box at Events/Tab features > Show Reload every ... (http://tmp.garyr.net/help/#Events_-_Tab_Features
). If you don't see those items in your menu, you probably need to show them first, Menu/Tab Context.
I don't know about your second problem, could be something happen during installation. You should be able to Import/Export settings w/out problems. It works for me.
This thread is about Tab Mix Plus v0.3.8.2
. Since you're talking about the latest dev.build, please, post in its designated thread (link in my signature).