why not to use virtual destructors

[sfx81]

Hi there. I was wondering why not to use virtual destructors in base class every time. Or more if I quote more accurately, what are the cases in which not to use virtual destructors ?
Any help will be appreciated.

[Duthomhas]

http://www.parashift.com/c++-faq-lite/virtual-functions.html#faq-20.7

Hope this helps.