It's very likely that you're experiencing a known issue, also with other browsers (e.g. bug #37974). Flash media are often wrapped in object/embed HTML elements. With the "pluginspage" attribute the author of the website can suggest a plugin download link. Browsers can relay that link when there is no plugin installed to view the media. There's already been some discussion about whether this is bug should be solved in browsers or in website authors [1].

If you're sure that the issue you're seeing is not related to the pluginspage attribute but coming from the browser itself, then please provide more details. Also check if you're using gNewSense's browser: it comes with a modified Iceweasel, not with IceCat.

[1] https://lists.nongnu.org/archive/html/gnu-linux-libre/2011-05/msg00007.html

If you use the IceCat web browser (which comes included with gNewSense 3) to navigate to a page that requires the Adobe Shockwave Player, IceCat will recommend installing the plugin. Although Adobe currently does not make an official build of Adobe Shockwave Player for GNU/Linux, this may encourage the user to find a way to install it anyway, such as downloading the Microsoft Windows version of the plugin and a browser and running them with Wine. Although this is not very major, this still needs to be fixed.