Premature withdrawal could prove painful -- to your pocket.

Federal Reserve Chairman Ben Bernanke is apparently set to stop the central bank's purchase of mortgage-backed securities in a few months, which could contribute to a full percentage point increase in the rates of 30-year mortgages.

Talk about shooting the alleged economic recovery in the foot before it has a chance to really get going.

Seems that Bernanke feels strongly, says a Bloomberg report, that by March it will be time for private investors to step in and start making the purchases in place of Uncle Sam -- or, in this case, Uncle Ben.

The problem is -- you knew there was going to be a problem, right? -- no one, including Bernanke, knows for sure whether there are any private investors willing to snatch up these mortgage-backed securities, sometimes more appropriately known in some circles as "toxic assets."

The average rate on a 30-year mortgage last week was down from a year ago largely because the federal government has been buying up housing debt. So, you can see why some are rightly concerned that an early federal pullout might pull up mortgage rates and derail any meaningful economic recovery.