I just have to ask why you are using MySQL if you want rollbacks, transactions, etc.

MySQL is built for speed at the cost of features. I imagine someday they'll fit in these features if they can figure out a way to do it which won't interfer with their primary goal. MySQL is good if you want a fast database and don't care about things like transactions. That's not what I'd opt for with an e-commerce site (although I would use it for something like a discussion site). Given the fact that you're talking about transactions makes me think that it's not the best choice for your project.

I would therefore suggest using Oracle, so that your boss has to pay and pay and pay like he deserves.

You might also want to take a look at PostgreSQL. It's open-source and supports transactions. Version 7.0 was just released about a week ago. That way you'd have all the features and the only code he'd own would be whatever you wrote to interface with the database, which he wouldn't be able to sell.

There was recently a discussion about MySQL, Postgres and ACID which you might find of interest, as you are bringing up some of the same issues.