If one hedge fund has their way Lehman Brothers will be joining Bear Stearns in Investment Banking heaven....or is that hell?

Greenlight Capital's David Einhorn has become a vocal thorn in the side of Lehman Brothers. After Lehman Brothers posted a $489 million profit for Q1, investors including Einhorn have been curious to know where the profit actually came from.

Mr. Einhorn, an admitted short of Lehman stock has called them out and put a spotlight on their mark up of lightly traded and hard-to-value equity positions to post unrealized gains in the previous quarter.

The WSJ reports that Mr Einhorn took issue with the unrealized gains and speaking at a conference, criticized them for writing down only $200 million of $6.5 billion in CDO's still on Lehman Brother's books. Lehman shares on thursday fell 2.7%.

Recounting his conversation with Lehman CFO Erin Callan, while declining to explain the size of the write-down, he said Ms. Callan added that "Lehman would expect to recognize further loses; in its second quarter."

More pain on the horizon for investment banks me thinks.