TinyMCE Plugin to insert content into HTML View

One of my exisiting plugins utilizes TinyMCE plugin system. The plugin uses a TinyMCE Popup via Thickbox and inserts content into the Editor only in Visual View, but not in HTML View.

This is the code that inserts my content into the Visual Editor:

window.tinyMCE.execInstanceCommand(
    window.tinyMCE.activeEditor.id,
    'mceInsertContent',
    false,
    content
);

When I’m in HTML view, the plugin works, but when I click “Insert” the editor’s content textarea stays unchanged. No errors being displayed either.

Does anyone have an idea on how to make it to work with regular HTML Editor?

Thanks!