Sorry - another newbie soft top question

[hoopyfrood]

and I didn't want to hijack SamPet's thread but....

The window on mind is starting to sag a little with vertical folds appearing across the length of the back window. It looks like it needs streching across the length of the car but that doesn't seem to be an option....

So, am I doing something wrong, have a missed something in the manual, is it an indication that the tops on its way out, or is it normal for this top happen in warmer (though wetter) weather.

[V8 GRF]

How taut is the rear section? The alloy struts need to be quite a push to lock, if they're not then it sounds like they might need adjusting to increase the tension.