According to another website: "Handwriting Expert Marcel Matley: "The last four lines of the suicide letter, which include the words 'I love you, I love you,' were written by a different person. There are differences in the two."
And:
"In 1995 Matley was part of a national commission that determined the authenticity of the suicide note of President Clinton's former White House counsel, Vince Foster."
Here's the CNN story