I have been using my laptop for 2 years and never had an issue like this. I keep it as clean as possible with 20GB space on the HD and regularly run AVG etc.
In the past few days when I have been using itunes I have noticed it jumping and skipping. It is not the actual music. It is the CPU reaching 100%. I am simply using firefox or Iexplorer but I have noticed that in the processes of task manager itunes goes up to 95-99% and jumps.
Or other times itunes will be 30%, firefox 70% and it jumps. Either way the CPU usage goes to 100% very frequently.
Is this an itunes issue? It doent happen when I am only using itunes but I notice it more then as the music jumps - but I'm sure it happen when itunes is not running also.