Comment 29 for bug 133677

My ACPI interrupt only seems to increase with ACPI related events, such as pressing the lid button.

I have my "timer" and "LOC" listings ticking up continually, as is the one shared by wireless / ethernet / video on my machine.
( watch -n 0.5 cat /proc/interrupts )

It is the timer interrupt which I thought might be an issue.

Are there any errors reported in your dmesg log? (Perhaps you could attach that).

I'm guessing the next steps to take might be to open a new bug with the kernel package for this issue, as it doesn't "seem" to be X11 related, and / or report this upstream with the kenel bugzilla. (I guess one of the Ubuntu kernel people might be able to help with that).