When plugging an iPhone to a Ubuntu machine for few times, the CPU becomes busy with 100% utilization.
This is due to some bugs which causes
iphone-set-info and sometimes
gvfs-afc-volume-monitor program to misbehave.
This is confirmed in Ubuntu 10.04
To fix this, run the following commands at the terminal
sudo killall -9 iphone-set-info sudo killall -9 gvfs-afc-volume-monitor
This will only kill the programs, and will not affect the iPhone's charging.