Tim,
Thanks for posting and I'm logging a case for this against case number 354161.
The only thing I can think of that's referred to directly as the Line Spacing is in the text tool- is this what you're referring to?
If so, I'm not able to replicate- Can you perhaps go into the text box you're editing, highlight the text, and try again? Can you please also confirm there are no extraneous line breaks in the text? Lastly, and pardon the question, but there are two buttons, one for increasing and one for decreasing line spacing- are you using the one to decrease?
If you're still having difficulty, or if you're using something other than the text tool, can you give us more detail or a screen shot? If needed, please call in and reference your case number and we'll follow up from there.
Thank you,