Two weeks ago, MF Global was hardly a household name, but its startling collapse is a sober reminder that whatever the root causes of the financial meltdown, they may not have been completely fixed. Indeed, in looking at the problems that may have played a role in the demise of MF Global, it is fair to ask: what have we really learned since we seemingly stood on the brink of economic collapse only three years ago?

While it remains unclear what happened to almost $600m of missing customer funds, what we do know is that MF Global's CEO, Jon Corzine, has resigned and the FBI, the Securities and Exchange Commission and the Commodities Futures Trading Commission are all investigating whether the firm improperly dipped into client funds to prop itself up near the end.

Although MF Global is no Lehman Brothers, it is the largest Wall Street bankruptcy since the financial meltdown. More importantly, it appears to highlight a disturbing pattern that we've seen before: the cozy relationship between government regulators and those who are regulated; a tolerance of dangerously high degrees of leverage; and an alarming lack of accountability in the handling of client funds.

Corzine, a former New Jersey governor and former Goldman Sachs chairman, has not been accused of any wrongdoing, but he played a central role in convincing the CFTC to hold off implementing regulations that might have prevented the company's collapse. While regulators were pressing to limit the ability of financial firms to essentially borrow money from their own customers, Corzine led the charge against the proposed rule, using his prolific list of contacts in Washington. In the end, CFTC chairman Gary Gensler, who had worked for Corzine at Goldman Sachs, delayed the vote on the new rule until the fall.

One of the hallmarks of the financial crisis was the degree to which firms became so highly leveraged that a run on the bank became almost inevitable. The level that MF Global was permitted to leverage itself should have raised red flags, but didn't. For example, it was reported that MF Global had liabilities at the end of June of $44.4bn against only $1.4bn in equity. That fact, coupled with the realisation that there was no primary regulator of MF Global, or brokerage firms like it, is even more disturbing. Instead, a number of regulatory agencies and industry groups each has a piece of the oversight. But with no one taking a look at the consolidated operations of the firm, it was difficult to impose strict rules regarding leverage.

Finally, the lack of accurate financial records is problematic. MF Global was required to maintain customer records and report correct information under both SEC and CFTC regulations. Failure to do so, or to falsely certify the accuracy of those records, would be a basis for potential criminal charges. With almost $600m of customer money missing and no clear record of where it went, it suggests a major failing in the record-keeping that was supposedly required by regulators.

While this investigation is just beginning and will likely take months to complete, what we already know is troubling enough. The story of regulators fixing the problem after the failure of a financial firm sounds all too familiar. Moreover, it seems that the patchwork of regulations and regulators may have allowed the full extent of these problems to go undetected. While more needs to be known before a final judgment is rendered, the real question may not be what have we learned from the financial meltdown, but whether we have really learned anything at all?