Mine was twice! Original owner @ 99k, then for me (2nd owner) @ 119k miles. Installed a zetec motor. Done with that c##p. When someone says they replaced the head after it happen and its all good. Ask them how many miles "all good" as mine went twice! Also, previous owner and myself drove it like adults. Nothing crazy.
-After zetec swap, car never ran right.
-Was a member of the "#2 dropped valve seat" club...Twice! Now a SPI->Zetec club member.