One further incident comes to mind which may be in the 'urban myth' category.
An internal flight to Las Vegas some years back reported a huge unexplained performance decrease - extended take-off run, low climb rate etc. All the load sheets checked out OK and the subsequent flight test was fine. A little further investigation revealed that the pax were all members of a numismatists club attending a conference in LV. Sooo ... ?? Numismatists, not surprisingly, like to carry their (very valuable) collections with them in their cabin bags. Each one had a sizeable collection of gold coins, in combination amounting to some ridiculous amount of unweighed load. Moral - money definitely CAN be the root of SOME evil.
