Ngubeni plays Thula while Ngqobe is known as Stone to the soapie's fans.
Ngubeni and Ngqobe are said to have been such a nuisance it became risky to even slot them into the script of the popular e.tv soapie because they hardly showed up for shoots.
"Sometimes they wouldn't even be available on their cellphones," says someone in the production team, who spoke on condition of anonymity.
"The excuses became so lame one would wonder if the idea was not to frustrate us."
The gatvol source says their characters could not be developed because at times a whole story would have to be changed to accommodate their absences.
"Something like that costs the production a lot of money. It's a total waste of time for everyone involved. They had become a liability."
e.tv spokesperson Matla Ragoasha denies the pair were bumped off the soap.
"Those actors work on a call basis and are therefore not slotted in because they are not full-time actors," she says.
Asked why other call actors appeared on the list, Ragoasha said she was not aware of any call actors being on the list. However, Sunday World can confirm that call actors like Moshidi Motshegwa appear on the list.
Ngqobe has bagged a number of awards, including best supporting actor and best actor in the soapie categories of the South African Film and Television Awards.
"I think those awards shifted his focus because after that he was no longer committed to his work.
"Sometimes he'd forget his lines," says one fed-up producer.
Ngqobe recently poured his heart out about his break-up with fellow actor Nokuthula Ledwaba.
While he blamed his absenteeism and apathetic tendencies to stress due to the break-up, our source disagrees.
"Speak to her. She probably broke up with him for the same reasons that he was fired for from the soapie."
Ngubeni is also no stranger to controversy - his character Jonathan Motene in SABC1's soapie Generations was dropped for the same misdemeanours, after which he made headlines by getting involved in a series of violent acts in 2008.
"Maybe he doesn't need the money. He drives a Hummer and his family business [Eclipse] produces most of the SABC1 gospel programmes and other Sunday shows," says relative Mary Chabeli.
"He will never have to beg anyone for a job."
Efforts to get comment from the actors proved futile.
ngudlea@sundayworld.co.za