Bloomberg Gadfly columnist Tara Lachapelle presents a column explaining the cash conundrum facing billionaire investor Warren Buffett. His company, Berkshire Hathway Inc., has been searching for acquisition targets that could help put its $116 billion of cash to use. Instead, he's now found himself on the receiving end of a possible transaction as Sheetrock maker USG Corp. -- in which Berkshire has a stake -- is being pursued by a German rival. Buffett has said that USG wasn't one of his best investment ideas, so he could be looking for an exit -- even if it means adding to his cash pile. This commentary aired on Bloomberg Radio.