This has been happening to me as well for the last three or four days. It has never been a problem in the past.
I believe there was an iTunes update on Wednesday or Thursday of last week and it has been a problem since then. When using iTunes my CPU goes up to 100% and stays there. The services using the CPU are iTunes.exe, ATH.exe and AppleMobileDeviceService.exe (all are obviously Apple related).
If I stop these Apple services mentioned above then my CPU drops back down to 2-3%. If I open iTunes again it doesn't take long before the CPU is maxed out once more.
Prior to this latest update iTunes has never been a problem on my machine over the last four or five years of use.
The machine in question is using Windows 7 x64 (with all latest updates), iTunes 10.7.0.21 x64.
This is a real problem as the machine becomes unusable until I close iTunes down. I usually leave iTunes open all of the time so that I am able to access music from my MacBook and other devices around the house.
Does anyone have any ideas?
Thanks in advance.