If you are running Internet Explorer 8 (IE8), recent updates to the list of sites run in IE7 compatibility mode may cause NSL 7.0 to miss clicking a button on the page that submits your credentials. This is because NSL 7.0 will be tricked into thinking the browser you are running is actually IE7 not IE8, and the way buttons are clicked is different on the two versions.
In the upcoming release of NSL 7.0 SP1, this issue is fixed. However, if you need a solution immediately, you may want to experiment with turning off compatibility view.
To do this, go to Tools -> Compatibility View Settings in Internet Explorer 8.
In this dialog, uncheck the “Include updated website lists from Microsoft” checkbox.
A better solution may be to simply use IE7 or Firefox for any websites that experience this problem, since unchecking this box may cause some websites to render improperly.