Extensions help!

Hi,

I can't get some extensions to work, for example this one: https://addons.labs.opera.com/addons/extensions/details/linkypic/1.0/?display=en

It seems to be all extensions that places a button on the UI. Is it because I have customized my UI, that no extension buttons are visible?

If I know where they placed their buttons I might be able to reintroduce that area if I somehow removed it...