The U.S. Roman Catholic bishops conference, a unified voice for more than a decade on secular and internal church matters, today shows signs of fraying around the edges.

The 300-member conference walked on eggs in the opening round of its annual convention as leaders sought to explain a stunning Vatican intervention into proposed guidelines to defuse problems between theologians and bishops.Hours later Monday, in another unexpected development, conference leaders pulled back a resolution urging renewed diplomatic ties between the United States and Vietnam. Two withdrawals in a single day was extraordinary for a body that prides itself on reaching consensus before ever going public.

Finally, by the time the bishops ended the rocky first session of their four-day meeting, at issue was a response to a Vatican statement limiting instruction authority of all organizations of their type.

That Vatican document, issued a year ago with a request for responses, was judged by a panel of past presidents of the National Conference of Catholic Bishops to be completely without merit. In a draft response proposed to the body of U.S. prelates, they urged a firm rejection of the view from Rome.

Yet even that response, which remains to be formally debated this week, fell under attack Monday by members of the conference, underscoring a current lack of consensus among the bishops.

According to conference officials, the tough response could be rejected by a membership that always seems to keep one eye over its shoulder as it struggles to assert itself to the Vatican.

The Vatican's power was unmistakable Monday as it intervened in the proposed statement addressing "doctrinal responsibilities" of theologians and bishops.

Development of the 57-page document, almost a decade of work, had been given particular emphasis by the Vatican's recent censuring of theologian Charles Curran, an instructor at the Catholic University of America who has dissented from church teaching on sexual questions such as abortion and homosexuality.

A draft of the document - which sat in Rome for 13 months, according to U.S. church officials - was to be presented Monday, setting out new guidelines for dialogue between bishops and theologians aimed at minimizing disputes.

But in a last-minute intervention, dated Nov. 10 and passed on to the bishops just this weekend, the Vatican alleged that the document treated bishops and theologians as equals and therefore was unacceptable - a characterization that frustrated American church leaders.

Bishop Raymond Lessard of Savannah, Ga., bowing to the sudden pressure from Rome, told colleagues that his drafting committee believed "the wisest course at present" would be to withdraw the document and to have a delegation meet with Roman Curia officials "to explain the intent as well as the content."

Lessard said despite his committee's belief that it had taken a "reasonable and fair approach," the Vatican apparently feared a threat to the instruction authority of bishops through the perceived equality with theologians.

As many continued to grumble, conference leaders then decided to withdraw the statement urging the United States to resume diplomatic ties with Vietnam.

Archbishop Roger Mahoney of Los Angeles, chairman of the panel that drafted the Vietnam resolution, said its "primary purpose" was to support, "on moral and humanitarian grounds, resumption of diplomatic relations."

"The church in Vietnam needs our help," Mahoney maintained. He noted the resolution was developed in cooperation with Catholic leaders in Vietnam, the Vietnamese refugee community in the United States - and the Vatican.

Nevertheless, pointing to the decline of the consensus that has been built within the conference by a moderate coalition under Chicago Cardinal Joseph Bernardin, Mahoney conceded a number of bishops privately "suggested ways the document could be strengthened."