Warren Buffett has received an unwanted check for more than $5.5 billion from Goldman Sachs. CNBC has confirmed the payment. It is right on schedule, but not welcome. One month ago on March 18 Goldman announced it was giving Buffett the required 30-days notice to buy back the $5 billion in preferred shares it sold to Berkshire Hathaway in September of 2008. That was at the height of the credit crisis. Berkshire's purchase of the preferred shares, in effect a loan to Goldman, was seen as a vote of confidence in the firm as some of its Wall Street rivals were going under. To buy back those shares, Goldman has to pay a ... (full story)