Midi doesnt rec. what i play in cubase 5.

Hello.
I am using Cubase 5, and i have recently had a problem with recording midi/instrument tracks.
The problem is that when i record a track using my midi keyboard, it doesnt record exactly what i play.
i can see that it records, but it automatically adjusts it, so when i play it back it isnt the same thing that i acutally played.
It is a problem that just started recently, so my guess is that i maybe have activated or deactived something in the program. I really hope you can help.
Regards