You're running Podium in Google Earth?
There is a very good free renderer called Kerkythea, and it has an exporter plugin for SketchUp. However, it takes a good bit more effort to set up than Podium does. You may get better results in the end, it'll just take more time on your part. Here's a link to an article about Kerkythea, which has a link to the Kerkythea website and the SU exporter.
http://www.alexschreyer.net/cad/renderi ... kerkythea/
If you want to keep working with Podium, I recommend going into the settings and fiddling with the speed and quality. This will increase the time it takes to render, but you'll get smoother, clearer results.