There’s growing speculation that a special investigation of Fannie Mae’s accounting procedures that was launched by the Office of Federal Housing Enterprise Oversight has uncovered serious problems at the nation’s largest GSE. But there’s no telling when the full picture will be revealed. Rumors began to swirl last week after news arose that OFHEO had submitted subpoenas against the company to compel testimony related to the forensic investigation. Although neither Fannie nor OFHEO would comment on