If you don't stipulate a font color, the site chooses based on the background you're using. If you do stipulate a color, it uses that color.
So, somewhere along the line, the color for your text got set to black - this can happen, for example, if you cut and paste from a word processor, or otherwise force the font to be something other than the default. Then, it shows up in black on a the black forum skin, and the statement is invisible.
If you go to edit the post, and turn *off* the WYSIWYG editor, you'll see the [color] tags around your text. The editor has a button to remove formatting (top row, second button from the left) if you'd like to fix it.
