FW: Paragraphs and headings overlapping in pdf output

[Brown, Nelson A. (DFRC-RC)]

I'm using the "aiaa-tc.cls" class v4.0.1 (http://code.google.com/p/aiaa-latex/) 
and LyX 2.0.5.1 in Windows 7.

I'm seeing a strange glitch in the PDF output where headings and paragraph 
texts overlap, or sometimes paragraphs overlap each other. (see links)

https://lh3.googleusercontent.com/-8k4GqMO9DjA/UeDrkUVgeRI/AAAAAAAAMLk/qvH7041JQT4/w753-h106-no/heading_placement_glitch1.png

https://lh3.googleusercontent.com/-g0e9urc52Ds/UeDrkeeIDzI/AAAAAAAAMLo/RHI0hCXgm78/w718-h293-no/heading_placement_glitch2.png

As I edit the text, the problem shifts from one section to another. That is, if 
I add some sentences to Section II, the heading overlap problem might stop 
effecting Section III, but starts effecting Section VII.

I haven't found any pattern to it, so far.

Ideas?


Thanks,
Nelson