Hi did you change your graphics card? what mac are you using , osx version , cpu type , speed . mac type? power mac mac pro?
ati cards can bug with the same graphical glitches .
what version of logic 8 are you using ? please can you update all OSX software via the Apple menu , Software update menu option.
You can try tuning automation off to correct some graphical bugs .
Minimizing and then maximizing the arrange page or mixer can also clear the graphical bugs .
Try Pressing "1" (for re-selecting screen-set 1)
Faulty RAM in the mac can also make this glitches less likely how ever to test this :-
To test memory is working fully you do need this tool :-http://www.memtestosx.org/joomla/index.phpEven if the Mac boots the chips may have errors in use , making random crashes or beachball problems. Please test ram with Memtest link provided above . there is no free way to do this effectively at this time , Memtest works perfectly and is a very good app..
The NVidia 8800 maybe a better option in your Mac if you have a ATI card , at least some of the bug are attributed to the ATI cards. i.e there are less bugs with the NVIdia 8800 graphics card option.
Logic 9 has ironed out many of these bugs , if you have an intel Mac it may be time to upgrade to Logic 9.1 , also please make sure all updates are installed . Keep doing software update if you have to restart , to find extra installs . Use Software update , each time you reboot , for two / installs / reboots . To make sure all software is updated ..
After all updates are run , you should repair permissions and check the mac HD .
Lets run though some basic repair checks .Repair Mac HD , Check Permissions with the OSX Startup volume.To check for disk errors and possibly fix issues with the Mac HD volume and other Partitions .Please run a Mac HD drive repair ,and Repair Permissions of the Mac HD startup volume .Review this video to become familiar with the below procedure .. http://www.youtube.com/watch?v=MFv3h7MVX4A&feature=relatedDisk Utility1 Start from your Mac OS X Install disc: Insert the installation disc, then restart the computer while holding the C key.2 When your computer finishes starting up from the disc, choose Disk Utility from the Installer menu.(In Mac OS X 10.4 or later, you must select your language first.)?Important:- Do not click Continue in the first screen of the Installer.If you do, you must restart from the disc again to access Disk Utility.3 Click the First Aid tab.4 Click the disclosure triangle to the left of the hard drive icon to display the names of your hard disk volumes and partitions.5 Choose your Mac OS X volume.6 Click Repair. Disk Utility checks and repairs the disk.If errors are found please run the check twice .Report any errors in displayed RED to me .Tip:- Always start up your computer from an Install or Restore disc when using Disk Utility to verify or repair your startup volume.**Perform Disk permission repairs while Booted to your Mac HD as normal**.Please run repairs on all your Mac HD partitions and disks.Choose in turn the drive name from the left hand list , and use repair .Run repairs twice if RED errors where found , check to see if they are now cleared.Using the Repair Privileges UtilityFor Mac OS X 10.2 or later, open Disk Utility found in the Applications/Utilities folder.Select your Mac OS X startup volume in the column on the left of the Disk Utility window, then click the First Aid tab.Click the Repair Disk Permissions button.Please wait while the Mac HD is checked.If errors are found please run the check twice .Report any errors displayed in RED to me .-Permissions DefinedMac OS X incorporates a subsystem based on a UNIX-style operating system that uses permissions in the file system.Every file and folder on your hard disk has an associated set of permissions that determines who can read, write to, or execute it.Now run some tests with your software and see if there's a difference ?-You can also try this more simple step to try to correct issues :-Turn off the Mac .Power on the Mac .Hold shift on the keyboard using a USB keyboard , while powering on the Mac and booting , boot to safe mode.Once booted to safe mode , restart and boot as normal .Full details here :-http://support.apple.com/kb/ht1455This may fix minor issues but it is best to run a Full Mac HD repair from the OSX DVD installer disk , use the OSX disk that goes with your current OSX install ..I hope this helps .Thanks .