Cecil, had you considered that Nutrasweetened beverages may have produced more foam than the regular variety due to the chemical nature of Nutrasweet being amino acidic?
Welcome to the SDMB, supercal.
A link to the column is appreciated. Providing one can be as simple as pasting the URL into your post, making sure to leave a blank space on either side of it. Like so: http://www.straightdope.com/classics/a2_043.html