As bad as the housing market has been, it appears that it was actually much worse.

CNBC:

The National Association of Realtors said a benchmarking exercise had revealed that some properties were listed more than once, and in some instances, new home sales were also captured.

"All the sales and inventory data that have been reported since January 2007 are being downwardly revised. Sales were weaker than people thought," NAR spokesman Walter Malony told Reuters.

"We're capturing some new home data that should have been filtered out and we also discovered that some properties were being listed in more than one list."

The benchmark revisions will be published next Wednesday and will not affect house prices.

Early this year, the Realtors group was accused of overcounting existing homes sales, with California-based real estate analysis firm CoreLogic claiming sales could have been overstated by as much as 20 percent.

There have been complaints about how the NAR counts existing home sales for years, largely because of the reasons given above. Apparently, the data wasn't fudged so much as it was bad methodology. The group is going to correct the problem, but in the meantime, the hole that housing much claw its way out of just got a little steeper.