Is there an order in which to display the blocks? I know when some were set to 0 (zero) by default they would not show....But then again that was the older system and I have not looked at the newest one yet to see if this has changed.
well I am not 100% sure on this but I know that it also depends on the theme you are using. Somtimes the theme is setup in a way that simply will not allow for the right blocks to show. I have noticed this on some of the newer themes were released.
Anyway, in the blocks section there is the option to have the block displayed in different areas. What area did you choose for this custom block you created?