A new HighRankings Forum thread asks if there is any downside in terms of SEO for using JavaScript that disables the ability to right-click on the page. The thread asks:

Most people in the thread say that it should have no impact on spiders crawling the site.

I then saw an older thread from Google Webmaster Help where Googler, JohnMu, said the same thing. He said and I bolded the key point:

Forum discussion at HighRankings Forum & Google Webmaster Help.