Beach Ball of Death and Freezing Apps

Question

For the past couple of days, I've been having some strange occurances on my 2007 MacPro (2,1) where, in certain apps, the Beach Ball of Death will appear and the app will freeze or hang.  I can be using the app for some time and perhaps do one thing, and the BBOD appears, the app hangs and the only way out is to Force Quit.  It has even happened once or twice with Finder which forces a reboot.
The app it tends to hang most in is Toast, especially when I go to burn a DVD.  It will start the burn process, then just hang (the optical drive will start to spin up-- as if to start the burn-- then spin down and the BBOD appears. A Force Quit ensues.  I can try to burn again and again but no luck, unless I restart the Mac Pro. Then it will work, no problem.
But it has also hung using Mail, Final Cut Pro, Photoshop and especially Time Machine.  I've gone as far as disconnecting Time Machine drive just to see if it is the culprit, as the majority of the initial hangs seemed to be associated with seeing the TM menu "clock" spinning, indicative of TM is doing a backup. Except the backup is taking forever and apps begin to BBOD as it spins.  I can check the TM Buddy widget, which just says:
"Starting standard backup
Backing up to: /Volumes/TM Backups/Backups.backupdb"
Normally there's a lot more information than these couple of lines, especially if TM has been going a while.
If I try to stop TM using the TM pulldown menu, the BBOD appears and it hangs, yet the clock icon continues to spin.  And if I try to Force Quit, it hangs (and on one or two occasions, the Finder has even showed a BBOD and hung.  And while I can move the cursor and click around the Desktop, there is no response.)  If I click on an app in the Dock, then the icon freezes in the Dock at its Magnification position and I can do nothing to make it go back. Then I usually just do a reboot and all is well for a while.
I did add two extra Gigs of SDRAM about two weeks ago (from Crucial) and no problem.  I did use Tech Tool Pro 5 and tested the Memory, which tested okay.  Also, I can check Volume Structures with Tech Tool 5 on the main drive and it says everything is good. (I have two internal spare drives and one external firewire 1.5 TB G-RAID) I've used Disk Utility on the OS drive and checked Verify Disk on the Startup Drive and the others and after awhile, it says the hard drive(s) seem to be okay. I've even ran Apple Jack to see if cleaning things up would help but no dice.
The only software I've added (on Monday and the problem started Monday) was a Seagate Diagnostic program to test some external USB Seagate GoFlex archive drives-- these are not always connected or mounted to the Mac Pro. When I started experiencing problems-- and it crashed or hung several times on Monday-- I trashed the Seagate Diagnostic program.  The TM has also been shut down and unplugged as I tended to see more hangs and BBOD when it was in a backup process.  (The first TM backup of the day goes smoothly.  An hour later, when it automatically begins another backup, the TM clock icon spins forever and trouble ensues as noted above)
I'm wondering if it is my main Macintosh drive.  It is a 250 GB drive, about 70% full and has worked fine until now.  Because the Finder continues to work, even though apps are BBOD or hanging, I'm not sure about that though.
Any suggestions would be greatly appreciated!  Thanks!

Answer 1

Do you still have the original installer dvd's?  If so run Apple Hardware Test.  Also since you recently added more memory also run Rember (a GUI layer on top or memtest).   I wouldn't trust TechTool for reliable memory tests.
The only software I've added (on Monday and the problem started Monday) was a Seagate Diagnostic program to test some external USB Seagate GoFlex archive drives-- these are not always connected or mounted to the Mac Pro. When I started experiencing problems-- and it crashed or hung several times on Monday-- I trashed the Seagate Diagnostic program.
Hmm, coincidence?  Maybe, maybe not. 
If the Seagate Diagnostic program was the one I found here you probably did not remove all of it.  Specifically the kext's it installs.
/System/Library/Extensions/MaxtorPowSecDriver.kext
/System/Library/Extensions/SeagatePowSecDriver.kext
If they are there move them to the trash (proably need your admin password to allow it) and reboot.
If the Seagate Diagnostic program is not the one I found. The do the following in terminal and post the results:
kextstat -kl | awk ' !/apple/ { print $6 $7 } '