I can't make heads or tails out of all these bank earnings.On the surface, it looks like we're seeing a clear divide between the winners and losers in the post-bailout era that is beginning. But below the surface, everything is muddled by one-time items, accounting changes and other gobbledygook. Some banks blame the government because of the cost of repaying taxpayer bailout money. Those that can't afford to pay back the government are saddled with the cost of paying preferred dividends to Uncle Sam (I look at that as a special bailout tax). Some banks say they are benefitting from improved investment returns and others are bemoaning the high cost of credit. It's all making my head spin. Yours will too after this quick review of what we've learned from the banks so far: Wells Fargo ( WFC) seems to be pulling out all the stops to prove it's the strongest bank alive, saying second-quarter profit and revenue set new company records that topped even the most optimistic analyst's prediction. Clearly, Wells didn't want to be outdone by Goldman Sachs ( GS), which earlier this month posted its biggest profit since becoming a publicly traded company on the back of big returns from its fixed income, currencies and commodities division. Citigroup ( C) did its best to stay in the game by producing a surprise profit that was bolstered by a one-time gain from the merger of its Smith Barney unit with Morgan Stanley's ( MS) brokerage business. Meanwhile, Morgan Stanley is blaming its second-quarter loss on an accounting oddity. Bank of America ( BAC) said its profit slipped a bit mainly because of the cost of paying preferred dividends (which go in large measure to the Treasury), but it still beat Wall Street expectations largely due to a series of one-off events such as the sale of stock in China Construction Bank.