crackling noise at recording

sometimes when I recording an audio track ,after taking the audio when playing the track getting crackling noise at audio clip where signal inputted , after exit cubase and re-open it at the same balance of audio mixture taking is ok,
so why getting crackling noise sometimes ?

ASIO straining under the weight. Try raising the soundcards buffers/latency.

A little more information would be helpful, but you probably need to increase the buffer size. What are your system specifications?
J.L.

cpu-intel core 2duo 2.8ghz ram-2gb os win 7,sound card- m-audio delta 1010lt
i am using buffer level 512

Depending on just how many FX/Vstis you’re running, as stated does the situation improve when buffer size is increased?