Help with caracter upgrade!

Hi!

I'm new to the forums, and this topic is about my recent problem with upgrading with this very good game.
Namely, i finished a couple of missions in chapter I, and it was hard to fallow the instructions in the middle of the chaos, but i somehow menaged to catch the most of them. BUT, the problem is with the technique upgrades. When i finish a mission, technique menu opens with a number of points to spend. It sais: press Space to upgrade. I tried it every time, but, only, when i select a techni?e (any) nd press space bar, nothing ever happens...
Can anyone help me, please!