I have a Hotas X Flightstick which i use only on Flight Sim X and this game. When i use it with the guns and the bomb run, i have a problem.
The left-right axis and up-down axis is "dead". Nothing happens.
Only axis working is upper-left to down-right or vice versa.

Can anyone help please?

That's a new one on me. Go into the game's control options and for pitch and roll test your joystick there for left-right and up-down movement. There is a gauge with a red needle that moves when it correctly detects the joystick moving in the appropriate direction. More details here : https://youtu.be/RMwKq7V0duU?t=46m15s

Yeah, its a strange one. I have the newest driver , and the joystick is brand new. In fsx it works flawlessly too.
Thanks for the tips on the needle. I checked it and it seems like here the game recognise the left-right axis. So a conclusion is that this problem only is in "action-mode"-when i use the joystick in-game.
I have done nothing edit in the keyboard-layout, or anywhere else in the game. It's all on default.

Very irritating problem, and really hope someone has a magical solution. :-)

Wow! Reset to default - everythings fine. I definately hadnt reassigned any of the keys, so this was a strange. Anyway guys, problem solved. Thx a bunch! Off to bomb some nazis now. :-)

Fantastic - glad it's now working.

@jayarrell - great tip suggesting the reset to default.