Is it the OS or the app?

Check your energy saver preference, check the crash log to see what process is running.

Also if you are connected to a network, or have Airport installed network activity may be set to a high priority.

File sharers are constantanly probing ISP IP addresses insearch of compatible host.

OSX also attempts to clean up caches, and other housecleaning. I leave my machine on 24/7, it's setup to do housecleaning and backup at 2:00 am

Not at my machine now, check the Apple knowledgebase for where to change the settings.

Originally posted by G-Dub:
I leave my machine on 24/7,

:) Hey G! You know, there is something to that, my co-worker popped several cards and power supplies with-in the last year alone.

In fact just yesterday Apple support was replacing a fried cap in one board of his system when I came in at 7am, they worked on it all night. He has a new system not even a year old yet. It is not uncommon for a batch of bad caps to find their way into the MFG sector. Panaphonic (sic) was plagued with this problem. Imagine having to replace tiny little caps on multi-layered cards. :d:

--Rick

Rick, I know as an electronic tech that electronics are most likely to fail on power-up.

It seems odd that a machine would, fail cosistantly at a certain time. Sounds like a scheduled process is interupting his fun.

andreasbert, are you the only user on this system?
Could it be possible that you have a back-up utility trying to access your volumes at that time?

:confused:

I'm a single user.
The only program that runs on crashing time is Protools.
And what's more , I do have to switch the machine off and on again with the power button. alt/option/esc doesn't work, ditto for the finder. escapod utility doesn't help.
I run janitor utility for manual clean up.
I'm connected to the inetrnet with ethernet.

Originally posted by andreasbert:
Why is my osx machine crashing every day at approx. the same hour, Between 10.30 and 11 AM.

andreasbert, just for the heck of it, flip the time 12 hours, if possible, and see if the problem continues.

Believe it or not, some local TV affiliates are testing their HD (open air) digital broadcast systems at specific times of the day. We have encountered many problems in the field, especially on VHF wireless systems at these times, so happens it is in the afternoon here, and is for one show only. Could be a digital RFI interference thing, leaking into your system somehow.

--Rick

In the Applications/utilities folder is the Process Viewer, open it before your next session. This will let you see what apps and services are running

Also at system level inside the Library/ Logs/ Crash Reporter.

It will tell the cause of the problem, chances are with OS10 your app was still running, but could not find the resources it was looking for.

I suggest repairing your permisssions with the Disk Utility.

When you shut down your machine manualy, the OS doesn't get the chance to do it's housekeeping. Minor file errors will happen.

If an app hangs use Force Quit under the Apple menu, then check your logs. :c: