Super Preview sucks - its basically an app wrapped around a service like browsershots.org. All you get are flat screenshots, which isn't enough.
You're going to need to find a way to test on a real version of the app. Xenocode(.com) used to have sandboxed versions of all the browsers available, which was perfect, but they've since removed the page. So now the images provided by MS (referenced in parent) are your best best.
Unfortunately they now require a plugin and launch from the web, they used to offer an exe of each browser you could download. Its too bad, was one of the best tools available for browser testing.
Ah - I'd always used the browser launch version, I wasn't aware they had .exe downloads.
I still think it's invaluable - rather than setting up three separate VMs, I can just have one on IE6, and launch 7/8 as needed (I usually just save-state at that point so I'm not constantly launching them).
You're going to need to find a way to test on a real version of the app. Xenocode(.com) used to have sandboxed versions of all the browsers available, which was perfect, but they've since removed the page. So now the images provided by MS (referenced in parent) are your best best.