[msuper69]

I have no idea why this started happening.

Running 10.6.3 on a MBA.

Started iMovie, Activity Monitor shows it is running an consuming CPU cycles but no blue dot under it's icon in the Dock. The application's user interface does not appear so I can't interact with it.

Same thing with iPhoto.

So I decided to do the old Windows remedy, reboot.

No difference.

Then I shut down. Waited a minute and started up.

Everything is now back to normal.

I would have thought that a reboot should have fixed any kind of temporary memory corruption within the OS but only powering off then back on would fix the problem.

[Spheric Harlot]

Were you able to start up Activity Monitor after this started happening, or was it already running?

Step 1, regardless of what might be going on: Make a backup of everything important on your hard drive.

[msuper69]

Originally Posted by Spheric Harlot 

Were you able to start up Activity Monitor after this started happening, or was it already running?

Step 1, regardless of what might be going on: Make a backup of everything important on your hard drive.

I have Activity Monitor in my startup items so it is already running.

I am using Time Machine for backups. I have used it to recover from fatal errors before and I monitor it fairly closely to make sure the backups are in fact useable (a trick I learned a long time ago-never assume that your backups are good but check them by doing a test restore).

The MBA is the 128GB SSD model, Disk Utility reports the S.M.A.R.T. status as Verified.

In the recent past, I've had problems where kernel_task would consume 150%-ish CPU with the system becoming very slow to respond to input. This still happens but rarely. I don't know what caused that to start happening and I don't know why it stopped.

Thanks for the input.

[reader50]

kernel_task taking up a huge amount of capacity almost always means a hardware driver issue. What peripherals do you have connected? Particularly ones that install their own kexts.

[seanc]

I think the kernel_task issue is related to Bluetooth.

As for SSDs I'm not sure SMART can be of much use for them.

[P]

If it happens again, check the Console (after reboot, if required) and post anything that looks fishy.