Recording problem with DJM 350

Hi Pioneers :-) 

Since over 15 years I dj solely with pioneer and never had any problems! Until now... 

I have a DJM-350, and two CDJs 800 MKII. It's a good basic set-up for home dj'ing in my opinion. I like to record my mixes. This feature of the DJM 350 worked perfectly fine until now. Now when I record a set and transfer it to my laptop and play it through my HiFi system I hear cracks and severe mistakes in the sound. It plays the whole set, but there are a lot of cracks and jumps in it. It sounds like a broken cd is playing. It's normally just a second or two, but showing several times in the set... And it seems to get worse as well. 

Does anyone know what I can do about it? I've tried different USB Sticks but that does not solve the problem. 

Thanks in advance for your answer!

Koen