The number of complaints in one week spiked at 151 just after the city's new parking machines were installed in July.
Council development services manager Kevin Thompson said most complaints could be traced to dirty or bent coins, foreign currency and other causes outside the council's control.
Only a "minimal" number of complaints, such as wet, illegible tickets being printed, were because of faults with the new and older parking machines, he said.
None of the machines had so far been found to be operating on the wrong tariff setting, he said.
Mr Thompson's comments came after Dunedin business director Ray Macleod approached the Otago Daily Times this week, saying he felt "short-changed" after a series of encounters with city parking machines.
He produced tickets issued by the same Moray Pl machine, outside Cafe Rue, showing a $3 fee placed in the machine on two separate occasions had resulted in different time limits being printed on the tickets.
The machine, in the council's new $3-an-hour "core" parking zone, had on July 18 given an hour's stay, but on August 8 it provided just 20 minutes.
Another brief stop several weeks ago, outside Whitcoulls in the $4-an-hour George St parking zone, resulted in Mr Macleod being given just seven minutes for a $1 coin - less than half the 15 minutes expected.
Mr Macleod said he was annoyed by the discrepancies, which came less than two months after the new parking machines were installed across the city.
"They invest all this money in this technology and twice in two weeks I have been short-changed, on two different parking meters.
"I don't mind paying parking fees . . . but I thought `$3 for 20 minutes?' I could do it cheaper in downtown Manhattan."
Other motorists might be unaware they were being caught out.
However, Mr Thompson said the Moray Pl machine - which was not one of the city's new parking machines - had since been checked and found to be operating normally, with the correct tariff set.
He suspected the error was caused by a fault with the coins used.
"There's nothing unusual about that at all. It happens all the time," he said.
Last month's spike in complaints, 151 in a week, was largely because of misunderstandings about the tariff zones introduced under the city's new parking regime, he said.
He advised motorists experiencing problems to call the council, and said traffic infringement notices would not be enforced where there were genuine faults with the machines.
