The examples may have a few typos or errors. They had to be changed to match v1.0 format.
Disabling or initializing the SD SPI is not needed, but is highly recommended. The alternative is suffering from the same problems I had with it. It only took me about a week of serious frustration to discover that was the problem. You will start to get trash on the SPI, but now right away. Mine would be fine for 8 to 24 hours, then trash, then crash. 