The Zairian government has so far been unsuccessful in repelling the invasion by some 1,500 Katagans from neighboring Angola in part because there is a "profound disaffeciton" with the government of the Mobutu Sese Seku among both the general population and the 40,000-man army, according to informed sources here.

Although logistical problems such as lack of fuel and spare parts for air transport have play a large role in preventing a quicker response to the invasion, these practical problems are apparently are not the only ones Mobutu faces in this lates threat to his rule.

According to one source, although Mobutu had expected an invasion of Katagan force in January, he merely reinforced the border guard at the Angola Zaire frontier town of Dilolo.

"One suspects he did not send more reinforcements to the Katanga region because he feared uprising in other urban areas," the source said.

This same source said that since the Zairian Army's defeat in Angola, where it supported a pro-Western nationalist movement, some army units have refused to go where they were ordered.

According to a U.S. embassy spokesman in Kinshasa, the Katangan invaders received a warm welcome in some villages. A former resident fo Katangan said this may be because the people in the region "remember the Katanga days as the good days." The "Katanga days" are the years (1960-63) the Moise Tshombe ran the copper-rich province now called Shaba. as a separate state.

The people, the former resident said, have complained that roads must be paid to get anything done. Another source said that teachers' and soldiers' salaries have sometime been "spotty - the money just never arrived from Kinshasa", the capital of Zaire.

An exiled anti-Mobutu leader, Antoine Gizenga , who supports the invsion, has said in Geneva that some Zairians soldiers defected to the invading forces after being defeated at Dilolo.

Other souces discount the disaffection in the Zairian army, however, saying that it is no greater than anywhere else" in Africa.

According to University of Wisconsin African history professor, Jan Vanisina, the disaffection from the Mobutu government was also recently expressed in a strongly worde pastoral letter sent out by Catholic Arcbhishop Kabanga in Lubumbashi which citicized the exploitation of te people by those in power.

Vasina said that Mobutu reportedly called in the Catholic bishops and demanded that they repudiate the leter, but they refused to do.

"There is a feeling of obsolutely everyone that the country is being plundered by the '200 families'," Vasina said. The '200 families" is a Zairian term for the privileged class that runs the country, he said.

The Katagan gendarmes who entered Zaire on March 8 are remnants of the army that Tshombe led first as regional leader of Katanganwhen Ziarew (then the Belgian Congo) became independent in 1960 and alter as head of a unsuccessful secessionist movement in Katanga which was finally put down in 1960.

The Katangan soldiers fled into Angola, where they have lived until now, often marrying Angolan women. The portugese who then ruled Angola welcomed the Katangans and kept them, as one writer has said, "in gilded capitivity" using them as leverage in their dealings with the Zaire govenment.

The Katagan gendarmes were put into action briefly in 1967 when French mercenary Robert Denard led a small group inot Katanga in support of an abortive mutiny in the Zairian army. When a spontaneous revolt against Mobutu did not occur to support the mutiny, the Katagans fled back into Angola.

They went into limo again until the advent of Angola's independence struggle when they fought on the side of the victorious Popular Movement for the Liberation of Angola (MPLA).

During this thime the Katangans who were mostly from the Lunda tribe in Katanga, livd in the diamond-mining area of Angola with their relatives among Angola's Lunda people. They made a living by farming and occasionally by helping the Portuguese in their skirmishes against the Angolan nationalist guerillas.

The exilde Katangans could easily slip over the border into Katanga during these years to contact their families and to slip typed notes in French under the doors of missionaries' homes advising them not to be afraid when the Katangese gendarmes eventully came home in force.

The leader of the invading force which appears to be heading for the copper-mining town Kolwezi is reported to be Gen. Nathaniel Mbumba.

Gizenga, a former vice-premier under the assassinated leftist Premier Patrice Lumumba, says he heads an anti-Mobutu coalition of political parties in exile, calims that his guerilla forces are still operating in Kivu Province about 400 mile from Katanga.

"We hope the Katanga patriots will be aable to link up with those in Kivu," Gizenga said.

It was Gizenga's gueriallas, called the Marxist Popular Revolutionary Party, who kidnapped four American students in May, 1975 from a research center in neighboring Tanzania.