RSS Viewer web part not selectable in Sharepoint Designer

I want to place the RSS Viewer web part into a page layout I've created.

In the Sharepoint Designer (Sharepoint 2010) using the "Advanced Edit Mode" I tried to add the RSS Viewer web part but I cannot find it in the list. Under "Insert>Web part" I find many other web parts but the one I need is missing, also under "More web parts..." it cannot be found.

The web part is installed (I activated the feature). The web part can manually be added to a page into a web part zone when I don't use the Designer but edit the page directly in the browser but of course this is not what I need as I have to put it in the page layout.

Anyone got an 开发者_StackOverflow中文版Idea why the web part is not selectable/visible in the list?

As I've learned not all web parts are available in this listing.

The workaround would be to manually add the desired web part to a webpart zone on the page (not in the designer) and then open the page in the designer so that you can copy/paste the web part relevant code to the page layout of your desire.