GIMP :: Separating Image From Background

Tried using this tutorial: [URL].......

trying to separate non-contiguous letters from a background so as to make the background transparent. I've used various methods including the gimp tutorial referenced above, and am having problems both selecting everything I need and with the transparency.

When I use the foreground select tool as in the tutorial, I can select the first line, 1812, but not the next two. Color values off some? Anyway, after successfully selecting at least the 1812 part, I do the next steps: invert the selection, add alpha channel, del background; and end up with a transparent background and a 'kind of' transparent 1812. If I try to save it as a png and open it in any other program it's just empty or black.