/var/db/BootCaches.playlist 2:no such file or directory appeared after Mavericks update

Question

Hi all,
I have tried to upgrade my iMac 2009 running 10.6.8, 3.06GHZ, 4GB ram machine and hit upon a grey load up screen and nothing more after the update. I have worked back through everything I could find in these forums as the bellow:
1. Completed all of the grey screen advice from Apple bar a full wipe and rebuild, but have left this as the last resort
2. Launched again from back up and reloaded Mavericks only to get the same problem
3. Tried to launch in Safe mode and the computer quits half way through the status bar and will not launch into Safe mode
4. Corrected all disk permissions in Disk Utility
5. Checked my EFI update and am running the latest version
6. Tried resetting the NVRAM but computer will not work from the keyboard shortcuts
7. Run Verbose mode where I could see the problem with loading Bootcache which produces the following script /var/db/BootCaches.playlist 2:no such file or directory
8. Created a carbon copy backup also and am now considering a full wipe
I have updated to Mac Book Airs in the last few weeks, and after the computer auto restarts the program then moves to a new processing screen where it finalises writing script, this point never happened on my iMac and after it restarted it just hung on the grey screen with the Apple logo. It is definitely in the Bootcache problem as this is one of te last processes and matches the amount of time the computer starts working before it heads into the grey hanging screen of death. This is definitely something that mavericks script alters, moves or deletes as I have seen this problem littered across the forums as well as the in ability for Safe mode now to work.
I am back up and running 10.6.8 at current and downloading a new version of Mavericks (more fool me). It could be a drive corruption but am unsure, but the computer s working well on 10.6.8 and has done for a very long time. Has anyone solved this yet, as t s driving me crazy!!!
Any Jedi's out there, I would be most indebted to you!
M-A

Answer 1

Hi all,
Well I thought I would re-post as have found a solution.
I created a bootable USB version of Mavericks using this article here which was very informative: http://www.techrepublic.com/blog/apple-in-the-enterprise/how-to-create-a-bootabl e-usb-to-install-os-x-mavericks/
I then rebooted via it, this again caused the grey screen of death as I thought it would, from reboot to reach this screen I held the Option Button. Before I did this I took a cloned copy of the hard drive and also backed-up again to Time Machine. Have over 470GB of music, photos and films, so yes was being a little over precautious.
I then rebooted and went into recovery mode (Cmd and R) and erased my hard drive.
I then rebooted once again but booted from my Mavericks USB version now with a clean hard drive, and set-up completed as expected with no problems. Its working beautifully at current but am yet to migrate files using the migration assistant, but once I have the new Mavericks version of my machine backed-up I will complete the migration, fingers crossed!
A few days of pain, but was a good learning experience. It was more difficult than it should be to created a bootable USB, but luckily I had another mac to work on and a decent back-up drive.
Hopefully helpful to others!
M-A