not exactly authoritative, but no need to search more after finding this one:
http://www.iidb.org/vbb/showthread.php?t=91824(But, methinks the IRS might be less likely to act now.)
"Lynn noted that the IRS in 1993 retroactively revoked the tax-exempt status of Falwell's television ministry, the Old Time Gospel Hour, for the years 1986 and 1987 after determining that the group had improperly channeled funds into a PAC supporting congressional candidates.
Falwell is apparently still smarting from that action. On CNBC's "Capital Report" July 2, AU's Lynn reminded Falwell of his run-in with the IRS. Falwell denied it had ever happened.
"Never," Falwell shouted. "Never. Never. Not one minute. Not one second. You are wrong.... Never one second did we lose our tax exemption." He later added, "You are telling a lie right now, Barry."
In fact, the revocation of the Old Time Gospel Hour's tax-exempt status is a matter of public record. On April 7, 1993, The New York Times reported that the IRS in February of that year revoked the Old Time Gospel Hour's tax-free status retroactively for two years for diverting assets and personnel to a political action committee. Falwell also had to pay $50,000 in back taxes. The federal agency required the ministry to issue a public statement signed by Falwell reporting the settlement."