Sound clucks NAND such. Are usually because your computer is not optimized for audio recording.
Go to windows.com or do a google search on ow to optimize your systemmforbaudio recording. This helped me a lot.
I've got the same problems with the crackling and popping noises. I found out that in my case this has something to do with my NVidia graphic card. On my notebook everytime when I change from the Intel onboard graphic card to my Nvidia card the drop outs/crackling appear. On my desktop computer they are always there .
Do you have AMD/ATI or Nvidia graphic cards?