Why do they do this? Usually it’s a misguided attempt to keep people from viewing the source of their pages or stealing their images, but all they really do is end up annoying their readers into never coming back. Ever.
Hint: it doesn’t really stop anybody from stealing. It’s the tech equivalent of searching 85-year old grandmothers on airplanes for knitting needles. If you do it on your pages, stop it now.
Open up the Tools \ Options panel, and then go to the Content “tab” on the top. You’ll see three buttons on the right-hand side, choose the one that says “Advanced”.
From this dialog you can uncheck the option for “Disable or replace context menus”. Note: If you also want to prevent websites from resizing your browser window, you can uncheck “Move or resize existing windows” while you are at it.
And now your context menu will work perfectly fine on the page.
It should be noted that disabling this setting will prevent customized context menus from working on sites like Google Docs… so it’s a toss-up on which feature you like more.