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Command-Tab [still] freezes system (sporadically) - any resolutions?

Someone must know how to kill the offending process (I hope).

This problem has been around for a few years now (i.e., both in Panther and Tiger) - but unfortunately, no one that I know of has posted a solution on the net as to how to recover usual operations from those times when the 'Application Switcher' (i.e., the one activated by command-tab) is stuck on screen.

The only thing that moves on screen is the mouse (usually stuck as a hand for me). No other keyboard shortcut makes any difference. I can ssh into the machine from another computer. But killing the dock, Finder or similar apps leaves zombie processes around and does not bring the gui back to life.

It seems to occur if you are too quick for the system (i.e., are able to command tab fast enough either to have done so before the panel appears on screen or have let go of the command key prior to it being able to get its required resources or something).

The only process on the system that has this problem of locking up the machine is the application switcher - there must be some way of killing when it hangs when such a thing occurs, but I've no idea what to kill.

Has anyone had success with recovering from this without rebooting the system from a remote system or holding down the power key?

Powerbook G4, 1.66 Ghz Mac OS X (10.4.9) 1 Gig Ram

Posted on May 2, 2007 9:03 PM

Reply
24 replies

Sep 19, 2007 3:08 AM in response to alphafoo

alphafoo wrote:
Would be nice if Apple would at least acknowledge this.


I filed a bug a while ago and recently asked for a followup (it was marked as duplicate). The response was "Please hold, all our engineers are busy with Leopard, so sorry."

YMMV but there seems to be a slight correlation between having CoreDuoTemp.app running in the menu bar and the frequency of crashes.

Sep 26, 2007 4:00 PM in response to Marsipan

Hey,

no solution here, just a confirmation:
I've got the same problem with my MacBook Pro, which I frequently connect and disconnect from a cinema display.

I used to always shut the MacBook down before connecting the display. No command-tab freezes as far as I remember.

Approx. one month ago I changed to connecting the cinema display while the MacBook is running. I now have those annoying freezes every couple of days.

Bottom line: According to my experience it might indeed have something to do with connecting an external display while the machine is running.

Sep 30, 2007 8:18 PM in response to lhmd

I am experiencing this issue as well -- it seems to happen as soon as I really start to get productive which is of course the worst time for a crash. There have been 5-6 times in the past two months where I get this specific crash. I am a recent switcher from PC, and I can safely say the Mac crashes magnitudes more than any of my PCs ever did. I feel that if Apple isnt going to address these issues, people should be made aware of them. They dont seem to be answering any of these problems on the support forum as well.

Oct 1, 2007 3:03 AM in response to bitwise

Hi there,

I am just another frustradted user who's experiencing this problem. For me it is totally unpredictable. The only thing I can say is, that it cannot be a total crash because some things (like Expose) are still "working" (Windows move but cannot switch apps).

I just made a clean install and the service has mounted a new harddisk (just to be sure). Then I had three days of error-free power-working and yesterday... I had a crash again...

Oct 10, 2007 9:42 AM in response to Koinseb

I also connect/disconnect from a external display frequently (currently a cinema display, previously a dell). The freeze can happen wether or not the display is currently connected.

On a positive note, I haven't expereienced a freeze since I replaced built in AppSwitcher with a third party one (LiteSwitch)a few weeks ago

Dec 9, 2007 6:07 PM in response to wr0ng

As mentioned this dose appear to happen after some random point after a display has been added or removed.

I had the lockup every happen other day (2 or 3 weeks back), usually at work, but only after attaching my computer to a TV the night before.

My current fix is to run 'killall Dock' from the command line just after adding/removing a display. No lockup crashes since.

the only issue is Icons such as Adium forget there state, so it looks like I'm off line, unless it updates again.

Apr 13, 2008 5:33 AM in response to ezterry

Hi all,

I am having the same problem (yes, I use external monitors at office/home) and I am going to try the 'killall Dock' method although it's quite passive.

Just added the following line:
*/10 * * * * /usr/bin/killall Dock
in my crontab. I will get back to this Forum if cmd-tab still freezes (I used to encounter this problem every 2-3 weeks or so, so maybe some other people in a worse situation may be more suitable to test it)

Does anyone know if this problem is fixed in OS X 10.5? Thanks.

--slyfox

Command-Tab [still] freezes system (sporadically) - any resolutions?

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