My 2011 iMac running Lion recently developed a new problem; the mouse cursor stutters. At random intervals when I move the mouse it lags, then jumps, like it missed a couple of frames. Ordinarily I'd blame my wireless mouse or system load or something, but the Console has this very useful note in it:

4/8/13 11:25:28.000 AM kernel: IOHIDSystem cursor update overdue. Resending.
4/8/13 11:25:28.000 AM kernel: IOHIDSystem cursor update overdue. Resending.
4/8/13 11:25:29.000 AM kernel: IOHIDSystem cursor update overdue. Resending.
4/8/13 11:25:30.000 AM kernel: IOHIDSystem cursor update overdue. Resending.

That suggests to me something is wrong with the rendering system, not the input hardware.

I've done some searches on this error and have found the usual superstitious-user suggestions for fixing the problem but nothing that seems to address how computers actually work. This writeup on StackOverflow is good but the question was closed before any answers came in.

Rebooting fixes the problem. The problem occurs even if the system hasn't been to sleep since a reboot. My system is unloaded, I have fresh batteries and a reliable wireless mouse. Problem also occurs with a wired mouse.

Update some of the research I've done suggests this problem is symptomatic of the kernel being busy and not servicing interrupts fast enough. I don't know how to verify that explanation or find the cause of the kernel problem if there is one.

  • Interesting. I've been having the exact same issue since a few weeks. 2011 iMac, running Mountain Lion. In my case it was because Transmit (FTP client) has a bad module. Apr 13, 2013 at 15:41
  • @TomvanderWoerdt I have this issue too. Can you explain more about your fix? How did you determine that Transmit was the cause? How did you resolve the issue (I'm not sure what you mean by "module").
    – Ashley
    Jun 1, 2013 at 13:36
  • @Ashley I had the exact same issue as described above when I installed Transmit and mounted a FTP server as drive. Rebooting did not help, uninstalling did.
    – Jojo
    Sep 1, 2013 at 16:23
  • Ah, thank you @JorisVanhecke. I was wondering how Transmit might cause an issue at the kernel layer... Transmit Disk (MacFUSE) sounds like a plausible explanation (presumably some part of that does actually run in the kernel, despite the Filesystem in UserSpacE name?). When I get a chance, I'll experiment and see if removing it helps me.
    – Ashley
    Sep 1, 2013 at 17:18
  • 1
    I started having this problem shortly after updating to 10.8 to 10.7 (currently on 10.8.5), on a Mac Pro 3,1 Someone posted somewhere (I forget where) that resetting the SMC (System Management Controller) might help. It did help for me, for maybe a week, but now it's happening again. I hope this isn't an early symptom of a major problem. How to reset the SMC can be found here: support.apple.com/kb/HT3964
    – Eric
    Dec 21, 2013 at 3:04

2 Answers 2


This is more of a comment adding data, but I'm not yet permitted to comment, so this will have to do:

I'm seeing this several times a day since getting my imac back from the shop with a new hard disk and Lion install, followed by a time machine restore. I also upgraded the machine to 32G of ram after it came back. When it occurs, the kernel_task in top goes to 95%. The problem goes away after a minute or two without a reboot or other action. There does not seem to be any disk activity, and I've tried replugging most of the USB devices since "IOHID" sounds like a USB thing, though I don't know that is the case. That didn't seem to make a difference however.


Your notes are fantastic and I hope that I can help in a small way. If the kernel is timing out and/or causing other processes to time out then it might be time for a re-install.

I agree that your mice are least likely to be the cause of your troubles but the OS remains a big suspect in my eyes.

I recommend going into the Mac App Store and under purchases redownloading Lion. This will automatically download the latest version (10.7.5)... For the time being stay away from 10.9 if you are truly looking for a resolution to the problem. Maybe consider 10.9 if the issue remains but best wait until 10.9.2 or so.

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