The pair built many of London's most famous contemporary landmarks together, including the "erotic gherkin" and the "wobbly bridge", but have been on no-speakers since 2003, when Shuttleworth quit Foster's firm to set up his own business.
Irked by this sudden departure, Norman Foster gained revenge last year, when (as Pandora revealed) he digitally altered a "team" photo celebrating the Gherkin, moving Shuttleworth to a less prominent position.
Now it's time for round three. Last month, milord Foster celebrated his 70th birthday by commissioning another staff photo, which was (rather oddly) then presented to his employees on a CD to mark the big day.
Considering this to be an act of breathtaking pomposity, Shuttleworth's firm got hold of the picture, and had it digitally altered, so that the front row of the commemorative photo is entirely filled by cut-out shots of their boss.
Copies of the new picture have now been circulated to employees of both Shuttleworth's and Lord Foster's firms, where - in the words of staff - they are seen as evidence of "yet more handbags between the old goats".
The stunt is already the talk of the arcitectural world, and yesterday both men sought belatedly to play down talk of a further public row.
Shuttleworth last night rather sheepishly admitted to being aware of the stunt, but pleaded that it was a bit of harmless fun.
"I'm not sure whose idea it was, but it's nothing other than a joke," he said. "I haven't spoken to him [Lord Foster] since I left but, as far as I'm concerned, there's no problem between us."
Foster, meanwhile, was said to be out of the country yesterday. Asked about the affair, an assistant said sharply: "He is not aware of the spoof photo."
* Great though it might be to get one over on Johnny Frog, winning the Olympics hasn't been universally greeted as good news.
Gordon Brown, for one, was forced to spend yesterday watching Tony Blair take credit for London's 2012 triumph. And if that wasn't bad enough, there's growing speculation Blair will stay at No 10 longer than originally planned.
James Naughtie goes as far as to predict he'll stay in office until 2012. In his speech at yesterday's David Watt Prize lunch, the Today anchorman said our PM "has that old glimmer back in his eyes".
Ominously for Brown, Naughtie recently wrote The Rivals, detailing Gordon and Tony's broken marriage.
* He's not the first rock pioneer to pick up a paintbrush, but Chris Rea is about (nervously) to go public with the fruit of his artistic labours.
In October, the gravel-voiced star holds his first ever exhibition, at the Cork Street Gallery in Mayfair. He'll show a collection of paintings used on his latest CD collection, Blue Guitars.
It completes a remarkable comeback for Rea, who was diagnosed with cancer a few years back. He came close to death, and says learning to paint has been instrumental in his recovery.
"My wife, Joan, is a proper painter, who studied at Goldsmiths, and when I was ill she got me completely hooked," he tells me. "It's become a huge hobby, and I now paint every day. It's an obsession."
Touchingly, Rea makes no claim to artistic greatness. "I'm not going to even have a private view," he adds. "If people love my pictures, then great. But I don't want to look like I'm trying to compete with proper artists, like Ronnie Wood."
* Proof, if it were needed, that the sprightly Sir Trevor McDonald, 64, has still got lead in his pencil. The veteran newsman has admitted to having the musical taste of a teenager.
"I didn't get to Live8, because I was in America interviewing George Bush," he told me at a fundraiser for the charity Harvest Help.
"I did go to Hyde Park recently with my son [Jack, 16] to watch the Red Hot Chili Peppers, though. They were fantastic, and we had a really good spot to see them. I'm really into Snow Patrol as well; I've got their CD in the car and would love to see them live."
Sir Trev makes an unlikely follower of cutting-edge music. A few years back, he admitted to an extreme fondness for the Spice Girls.
* After all these years, Christine Hamilton still sparkles in her role as the undisputed queen bee of British battleaxes.
Just ask the Daily Mail columnist Richard Kay, who met Hamilton at Sketch restaurant on Tuesday. According to several eyewitnesses, the duo began a heated discussion, during which Kay - a gentle, softly-spoken individual - was bopped on the nose.
"Christine's opening gambit was to say 'I'm sure you don't personally write all those nasty things about me in your column'," I'm told. "Richard replied that actually he did, and the next thing we knew, he was sent flying."
Friends of Kay say he's in a state of mild shock. Hamilton, meanwhile, denies throwing a punch.
"I've never hit anybody. Not [Mohamed al-]Fayed, or Martin Bell, or even my husband," she tells me.
"I did pop a napkin on Mr Kay's head, in a playful way. But if that's interpreted as fisticuffs, people are being pretty pathetic."Reuse content