Help GTA4 the final mission - Helicopter jump **may contain spoilers**

[#1]

Out of Commission This mission on the pc is starting to annoy me, all the forums I've checked say mash your space bar to climb into the helicopter but everytime nothing happens.  I've tried macroing it with my G15 and still can't do it adding 0.1 too 0.5 second delay between key strokes.
So to those that have done it, what is the secret?  Final mission and its very annoying that its down to pure luck and almost killing a keyboard to make it.
edit: meh wrong mission name

[#2]

I always use Google for that sort of thing.
http://www.gamefaqs.com/ is pretty handy I've found.

[#3]

Which say's exactly the same thing, simply mash your space bar which I cant believe its 100%, I've seen video guide on youtube and its done first time so there has to be a knack to it unless the pc version is buggier than the Xbox which it was for.