Once you have loaded a script onto the page, it remains active until the page refreshes.
I don't know about unloading, but you can certainly disable the actions of a certain script depending on what it is. Could you post an example of the script causing the issues?
EDIT:
For example, if you have a script that is dependent on the tab you are in, you can condition the actions in the script with the tabs being at a certain index. A demo syntax:
//will only execute action if you are in current tab
if(tabs_ui_index == 0){
//do something
}
to get that variable (tabs_ui_index
) you can do something like this:
$('#mytabs').bind('tabsselect', function(event, ui) {
tabs_ui_index = ui.index;
});
This code binds a "tabsselect" event to the element that is tabbed and sets the variable to the currently indexed tab every time a user changes a tab.
Also, you can unbind events, if you loaded a script that set a click event for a button that no longer exists, or that you are using for a different purpose now:
$("#mybutton").unbind("click");
I hope this helps. Let me know if you have any other questions.