Strange cpu activity when uploading(?)

[vampm]

Hi! I have p4 @ 2.4ghz and XP pro 32bit. I have utorrent ver 2.2.1 (and 2.2.2). When uploading, the task manager shows usage peaks, like this,

^ ^ ^ ^ ^ ^ ^ ^ ^

like bursts, at about 35% of the cpu. The peaks are almost the same, like they take the same amount of cpu every time.

This is surely from utorrent.

Is this normal?