If ever there was a lesson to be learned from the spate of catastrophes precipitated by the credit crunch, it should be that mistakes made in the past should be remedied to prevent future problems in the market.

But yesterday's reports have shed new light on how far the UK authorities are from having a strong handle on current market activity. New rules introduced last month that oblige UK-based hedge funds and other investors to disclose short positions in companies conducting rights issues have caused confusion, according to the Financial Times.

Almost half the disclosures made by hedge funds to the Financial Services Authority so far have contained errors. According to the FSA, 20 of the 41 disclosures missed filing deadlines, contained the wrong figures or were not even required (one firm reported a short position in a company that had not in fact launched a rights issue).

The mistakes illustrate the difficulties faced by hedge funds and other short-sellers in applying rules imposed by the FSA with just a week's notice. The UK regulator used emergency powers for the first time to bring in without consultation regulations requiring the disclosure of short positions amounting to 0.25 per cent or more of the stock of a company going through a rights issue.

'We are aware that it is early days, but we are keeping the technicalities of the disclosures under review,' the FSA says.

After all that has happened in the last year or so, the financial watchdog might have been expected to respond in a more considered manner, rather than forcing through new measures that to some observers smack of panic. The haste of their introduction, and the problems practitioners are encountering in complying, do not leave the impression of a financial market under calm, authoritative supervision.