[Inkscape-user] Slicing and selecting

Hi, Found myself trying to slice-up a page and realised that I can't select the rects that are 'invisible'. I make them alpha 0% so they won't show, but then I can't select them.

I followed HeathenX's tut on youtube, doing everything the same way, but he selects the hidden rects click-click no problem, I can't do that on my end.

Is there some trick to this?

\d