After saving project, I have a buzz sound when I press play.

So, the problem is. When I save a project, I open it (it loads normally) but when I press play all I hear is buzz sounds. (I almost blew my ear drums when I had my headphones on). It's been happening for about 2 weeks and I can't fix it. When I look at waveforms of samples in these projects, they are just straight plain. When I export a song to a final form, there's no problem but when I want to save a project for later, I can't.

Edit: Forgot to mention, I got akai mpc studio.

Screenshots:


Here how samples look after saving a project and loading the project: