I just installed ubuntu 12.04 on my powermac g5 quad, and It works almost perfectly. The only problem is with the icons in the unity launcher side bar. The top icon shows some orange but it and the rest are mostly white. Does anyone know what is wrong or how I would fix it? I couldn't find anything on the web.

Also, I have a Nvidia Quadro FX 4500 graphics card. Is that the problem?