Finding that I get what looks like display memory corruption sometimes when using iMovie which leads to OS instability. I've had to restart my iMac several times. Once, the UI completly froze and I had to power it down hard. Also ended up with disk corruption and had to go into single user mode and run FSCK.
iMac (21.5-inch Late 2009), iOS 7.0.4
Back up all data immediately as your boot drive may be failing.
This diagnostic procedure will query the log for messages that may indicate a system issue. It changes nothing, and therefore will not, in itself, solve your problem.
If you have more than one user account, these instructions must be carried out as an administrator. I've tested them only with the Safari web browser. If you use another browser, they may not work as described.
Triple-click anywhere in the line below on this page to select it:
syslog -k Sender kernel -k Message CReq 'GPU |I/O e|find tok|n Cause: -|NVDA\(|timed? ?o' | tail | open -ef
Copy the selected text to the Clipboard by pressing the key combination command-C.
Launch the Terminal application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.
Paste into the Terminal window (command-V).
The command may take a noticeable amount of time to run. Wait for a new line ending in a dollar sign (“$”) to appear.
A TextEdit window will open with the output of the command. Normally the command will produce no output, and the window will be empty. If the TextEdit window (not the Terminal window) has anything in it, post it — the text, please, not a screenshot. The title of the TextEdit window doesn't matter, and you don't need to post that.
I did this. Nothing was returned (Textedit was had a blank document), and the command ran very quickly. Couple of this, first, I got the OS version wrong, it is 10.9 (Mavericks). Also, below is a picture of what my sceen looks like when this happens...
I suspect you have a failing graphics card. If you can run Apple Hardware Test in extended modeat least 3x back to back. If you get error's then that has confirmed failing hardware which cannot be fixed on this forum. In short the next step would be a visit to your local Apple Store or AASP for repair. To learn how to run AHT then click:
Make a "Genius" appointment at an Apple Store, or go to another authorized service provider.
Back up all data on the internal drive(s) before you hand over your computer to anyone. There are ways to back up a computer that isn't fully functional — ask if you need guidance.
If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to an empty drive from any of them.) Don’t erase the recovery partition, if present.
Keeping your confidential data secure during hardware repair
*An SSD doesn't need to be zeroed.
Thanks for the advice. I did run AHT once last night and got no errors. I will try to run it a few times tonight,
Is anyone seeing OS stability issues with 10.7 when using iMovie?
