It had nothing to do with James A Michener's storyline, set in 1949, of a racially blinkered nurse from Little Rock who falls in love with an exiled French planter who has two Polynesian kids.
No, the cringe moments came when the actors burst into cheesy songs such as There Is Nothing Like A Dame.
"Yes, it did nothing for me," says the former EastEnders actor who hit the headlines in 2002 when beaten little Mo smashed an iron on to the head of her abuser, Trevor.
"South Pacific, for me, was all about images of cocktails and beaches. But last year my agent called and asked if I'd be interested in reading the script for the theatre production.
"I read it and realised it was essentially a great play written to music, all about race, the impact of the Second World War, and people's insecurities and fears.
"It's a dark play, but it's also very funny. So I went to meet the director and realised this production had been massive on Broadway and won several Tony awards."
Alex, who grew up in Lennoxtown before emigrating to South Africa with his family as an 11-year-old, liked the idea of playing the ebullient Luther Billis, so took the part when it was offered to him.
"He's fun. But I also love the range of work theatre can offer," says the 43-year-old, who played The Hard Man in the Jimmy Boyle bio-play last year and recently starred as the psychotic doctor in Little Shop of Horrors.
Talent has a great deal to do with. Many actors can play a single character, but the measure of a performer can be gauged by the variety of roles they undertake.
Alex Ferns does a great psycho, but he can also convince in light comedy or straight drama, such as his ship commander role in the BBC drama, Making Waves.
Yet, while he acknowledges part of his career success has been down to his award-winning EastEnders performance, he reveals his stint in Albert Square was coloured.
"When I took the job I'd been struggling for a couple of years, having come to London from South Africa. In fact, I was on the bones of my a*** .
"And when someone offers you a big pay cheque, it's hard to say no. Yet I had no idea what it would all mean, the huge audiences, people recognising you where ever you go.
"I'm incredibly proud of the work, and it was a great storyline. But it closed as many doors as it opens."
Being cast as the psychopath has resulted in a degree of typecasting. But if he had his time all over again, would he take on the role of Mad Trevor Morgan, the man who became reviled after he pushed Little Mo's face in her dinner, and made her eat off the carpet?
His voice softens as he answers: "No, I wouldn't have. I'd have preferred to stay under the radar and do my work."
Alex Ferns, you sense, would have done very well in the business without the soap. He can convey emotion. He gets nuance. Film work such as the gangster thriller Man Dancin' convinced he has real depth.
And acting was always in his blood. The seeds of acting potential were sown in Scotland. Young Alex was a joker, but after his first school play, aged 10, he landed the lead in Pilgrim's Progress and knew then he'd eventually appear on the professional stage.
The dream continued after the family emigrated to South Africa. But when Alex declared his intent to become an actor, it caused problems.
"I was never good at anything else," he says, modestly. "But there was a lot of conflict about that decision. My dad wanted me to get a trade, to make sure I'd work. But I couldn't."
Alex's parents divorced in 1996 and as a result he saw his dad only 0ccasionally. They hadn't spoken for five years when his dad was killed in a car crash in 1998.
Did it leave him full of unresolved feelings? "No, not really," he says. "You see, when he died I learned that he had this file of newspaper cuttings about me. It's so typically Scottish. Scots seem to find it hard to show emotion to those closest to them.
"My dad was like that. He'd never mentioned my acting far less offered me a slap on the back. I guess because he found it hard to admit he was wrong."
Alex said: "I never stopped loving him. Sure, there was animosity at the time, but that happens. And who's to say he should have known better?"
Alex now lives in London with his wife Jennifer and their two sons, Cameron and Mackenzie,
"I'm the only dad actor in their school," he says. "My four-year-old isn't too aware of what I do but my nine-year-old revels in it. I think what I do is just a job but you forget how the work can impact upon people."
The actor is aware how South Pacific is impacting upon the nation right now, an upbeat musical perfect for a downbeat economy.
"South Pacific is real fun," he says. "It's also nice to play a guy who's not a lunatic."
The tour has produced some very good reviews for Alex.
"I only read the good reviews," he says, grinning. "You wait to hear the word on the street before opening the papers."
l South Pacific, Tuesday-Saturday, Theatre Royal, Glasgow.