Are these plug in elements ?
If so the scraping earth may be corroded and not making a low resistance contact to keep the outer element casing at earth potential.
If an element is on the way out, the internal resistance wire may be touching somewhere to the outer casing.
Sometimes that is very visible as a hotspot which is a lot brighter light yellow orange than the rest of the elements while on full power.
When the earth is high resistance there may be a certain amount of leakage which may cause part of the power to leak through the casing to earth and a higher current will be drawn from the supply untill the element burns out, and will cause a rise in potential of the actual element casing.
edited for typo's RF.
[This message has been edited by RODALCO (edited 11-02-2006).]
