NEED HELP WITH GTA 4 PC D:

ok now guys i have gta 4 on pc. if an of u guys played and finished it u know that there are 2 endings, i chose the revenge and blah blah. then theres a mission where u have to chase down pegorino then he tries to escape on boat but im chasing him with a bike on the beach. then theres Jacob's chopper and i have to jump onto it when i hit the ramp. I get to that point but when i have to climb the chopper...nothing. Ive tried everything, ramming the climb up button, changing the controls, EVERYTHING. I can see his hands pulling up to the max but he just doesnt pull up finally. I did the mission like 40 times and failed jus cpz pf that dam chopper climbing thingy. Anyone that knows the issue pls help. Ive got an awesome PC , gta runs very smoothly and the game is 1.0.4.0 version. PLS HELP!

just get below the heli and you will auto get up, taking the money deal is better though

Visit this site:
www.gta4.net It has all things you need to know about the game.
Select Walkthrough and select the mission that you are playing
Hope it Helps.