Theoretical Whizzing: Good and Bad Electrolytic Capacitors

[Jim]

Rob Funk asked about bad electrolytic capacitors: 

> Any idea how they get bulged?

I first heard of this two or three years ago from an EE friend.  
He said that a bad batch of electrolytic had been used for some 
capacitors.  I think the problem is too far widespread to blame 
on one batch of juice, although a bad recipe could cause problems.  

I don't have any solid understanding of the failure mechanism.  
Here are some articles that seem plausible to me: 

   http://www.niccomp.com/taiwanlowesr.htm
   http://www.siliconchip.com.au/cms/A_30328/article.html

So it seems my EE friend was on the right path.  

http://www.google.com/search?q=electrolytic+capacitor+failure+bulged

I recently got a dead motherboard.  The caps were bulged.  
I've replaced them, but I don't know yet if the board is still dead, 
since I don't have the right CPU and memory on hand with which to test.