10.6.6 update problems for MySQL

Question

I tried this in another area, but received no responses... trying again here.
I just performed the 10.6.6 update and following restart, I can no longer get MySQL to start up. There was a similar problem with a previous update (I believe in Oct 2010). At that time, MySQL was starting up, but Apple had changed the location of "mysql.sock" (socket file) to a non-standard location (from "/var/mysql/" to "/tmp"). Unfortunately they forgot to tell users that they were doing this and it about a week before someone (a user) discovered the source of the problem and create a solution. As a full-time, large-scale web developer, that cost me a week's worth of income!
Once again, MySQL will not start up, but apparently for totally different reasons (and again without any forewarning from Apple. MySQL will not start from the command line either, but gives no indication why it fails. I've now spoken with 3 Apple Support techs, including a "Senior Advisor". None of them even knew that MySQL was part of the standard OS-X installation!
Has anyone else experienced this problem or could suggest possible solutions? I am desperate to get this figured out, as I'm supposed to fly out of Denver to New Orleans on Monday morning to do a major site installation and I can't even get to the data on my MacBook Pro to upgrade the MySQL installation on my web servers.
HELP!!!

Answer 1

After trying everything I could think of, I finally just gave up and did a clean reinstall of the MySQL application. At this point, I had MySQL loading again. At some point, it mysteriously quit working again, so I repeated the process. Unfortunately, since I reinstalled the same version as the previous, the NEW install overwrote the OLD install and wiped out over 100 databases (48 active, the rest backup and Dev versions) during the installation.
No problem, right? I'll just recover from my Time Machine backup. First, however, since I've been traveling over the holidays, my most current Time Machine backup was Dec 17. Second, I couldn't figure out a way to get Time Machine to restore anything in the hidden directories (/etc/, /usr/local... ), without doing a full reinstall, which would have resulted in loss of considerable work performed in the past 3 weeks.
Logging into Terminal as root, I was able to walk my way through the various backup folders in an attempt to find the most recent backups of each database. After 36 hours of continuous tinkering (counting a 7 hr span to create a fresh "clone" for safety), I finally have it working again. I know without a doubt, that I've lost a great deal of database work, which will mean doing a lot of duplicate effort. But at least I'm up and running again. And I realize that on a Windows box things could have been much worse. But who wants to do anything twice (unless you get paid for it both times)?
In short, there was no quick and easy "solution". The lesson to be learned? Never, never, never do a simple OS upgrade, without first doing a full backup (even if it does take 7+ hours)! I hope this at least helps someone else avoid the same headache.
Thanks for your feedback.
Jack