@Lucas: If create a new feed or rename a feed on the iTunes/Feed settings page in the section podPress Feeds then you need to save the Permalink settings afterwards (don't change them; only save them again).
URLs like:
http://thesimplegamers.com/?feed=podcast
should work always as long as the feed is activated.
http://thesimplegamers.com/feed/podcast (which is basically the same) will work only if save the Permalink settings e.g. after the activation.
These podPress Feeds are no category feeds. They are additional feeds.
podPress also allows you to customize category feed title. You can find the necessary options under Posts > Categories > Edit Category section podPress Category Casting.
When exactly does the Image disappear? When you start playing one episode?
In this case it is a different effect. If you play an episode and only the place holder icon is visible then it means that your media files do not contain cover images. You can add such pictures to each episode e.g. with the iTunes client software or other authoring software before you upload them.
Furthermore the RSS image which should have size of 144x144 pixels is 300x300 pixels. ("http://img696.imageshack.us/img696/5201/simplegamerscover.jpg")
The iTunes image should be at least 300x300 pixels. But it is recomended to use a 600x600 pixel image.