MPC freezes in LOAD mode.

Hello. I am fresh owner of MPC 4K, everything is fine, except one thing: when I want to load sample from pendrive it mostly freezes. What is most annoying it freezes only in one folder - Breaks (about 500MB). I've tried other pendrive as well and again it freezes only in folder Breaks. I've tried to use Ak.sys to copy these samples directly to HDD, but it caused error. When I was using computer or MPC1000 this folder was working correctly and I had no problems.
This is VERY annoying...

!BUMP

Again I have a problem. I don't know is this a pendrive problem or something else but this is **** annoying.
1. I've choped long sample in sound forge called it: x1, x2, x3, x4
2. I've put it on my pendrive in folder called x
3. I connect my pendrive to the machine
4. I go to LOAD mode, locate my folder and press DO IT
5. x1 loaded, x2 guess what .... FATAL ERROR

I don't know, I like this MPC but I can't load my breaks and now I can't load my samples. I want to make music but how can I make it without sounds? This thing really freaks me out. WHAT THE ****? argh...

Maybe I have some viruses on computer, could there be any connection with this?

and btw. I got a blue one.
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It freezes in other BIG samples. Does MPC 4k have limitations in sample size?