I tried my hand at making to themes for my 8700c. I loaded them onto my bb along with the plazmic theme reader. But when I went to set them to active they just came up with the blue sky background and not the background I loaded. Was it because the background pic was greater than 60K?

yes reduce the image file size to under 60kb and it will then show as your background after you have loaded the theme.

use a graphic editor to edit the image and try saving the image a .gif or depending on the editor try file/save for web feature it will also reduce the file size for you.