Gramps always warned that rock 'n' roll would cause permanent damage, but it may be gramps who ends up suffering the consequences.

A Michigan State University study found that iPods, those ubiquitous portable music players from Apple Inc. (NASDAQ: AAPL), could interfere with implanted cardiac pacemakers. Electrical interference was detected half the time when the devices were held to the chests of 100 subjects with pacemakers, as far as 18 inches away from the chest, and in one case caused a pacemaker to stop functioning altogether.

Scary, huh? Of course there's no reason just yet to start tossing iPods onto the bonfire or e-mailing warnings to everyone and his uncle. It's only one study, and the lead author of the study is a high school student from Okemos, Michigan, though he is the son of an electrophysiologist father (who gave him the idea for the study) and rheumatologist mother.

As some have pointed out, however, pacemaker patients don't tend to be iPod users these days. A little caution never hurt anyone, but neither did a little common sense.

This story reminded me of the recent warnings about wildly popular Crocs (NASDAQ: CROX) posing a hazard in hospitals (as well as more recently about Crocs and escalators). Yet when I visited someone at the hospital last week, I noticed that the colorful plastic shoes were quite popular with the nurses. So who knows?

Not that these stories necessarily fall into the category, but isn't it funny how the most popular products always manage to spawn urban legends?

Boston Scientific (NYSE:BSX) issued a weaker than expected forecast for Q3 2006 revenue and earnings, based primarily on problems associated with its pacemakers and defibrillators. These were the products manufactured by Guidant Corporation which Boston Scientific acquired in April 2006 for $27.5 billion. At the time of acquisition, Boston Scientific knew of at least 500 cases against Guidant in the U.S. The suits have since been consolidated. The suits allege that Guidant's cardiac pacemakers and defibrillators are defective and have the possibility to cause harm or death to patients in whom they have been implanted. Boston Scientific has set aside $381 million for legal defense costs, but still does not have an accurate estimate of the cost to settle all the suits related to Guidant's defective products. Also, Boston Scientific's own product, a drug-coated cardiac stent used to open clogged arteries, has suffered a decline in sales as heart surgeons turn to alternative devices perceived to have a lower risk of causing blood clots.

Q3 sales had originally been estimated at $2.18 billion, but have been revised downwards to just under $2 billion. Q2 stent sales in the US were $429 million, but Q3 sales are forecast to drop to $375 million. Global stent sales for Q2 were $647 million, but Q3 global stent sales are forecast to be approximately $565 million.

Boston Scientific stock lost 9% on Friday, 22 September, closing at $14.85, down $1.51. Do not look for an improvement in Boston Scientific's stock performance until the suits are settled or a ballpark settlement estimate has been made public.