Should the Mark to Market Accounting be more relaxed or kept the same?

Mark to Market is the accounting rule that makes banks account for the value of assents on their balance sheet at the price of the most resent sale. In this case.. since mortgage backed securities are being forced sold (ie Lehman bankruptcy) into a market that is so thin, the prices are artificially low and banks are having to account for them at these low levels and that is what is putting their balance sheets into trouble..... this is the meat of the problems with the banks today.