A week ago today, Dennis Palladino walked into an ambush of 31 voice-mail messages from Easter chocoholics.

The callers had failed in their last-minute search for a fix of Zitner's Butter Krak, Butter Cream Cocoanut Cream, peanut-butter- and marshmallow-filled eggs. And they were anything but sweet about it.

Where are my Zitner's eggs?

I went to the store, but the shelves are empty!

Why can't I find your candy?

For days leading up to the holiday, the one-of-a-kind North Philadelphia chocolate factory, worshiped in the region for its once-a-year Easter egg confections, had been inundated with frantic calls.

Philadelphians had busted down the doors for Zitner's eggs, but in numbers that left some retailers with empty shelves a week before the big day.

Given how the recession has led to penny-pinching on indulgences of all kinds, it's an egg-consumption mystery that company officials say will take at least a few weeks to crack.

"We sat here and talked about it every day, trying to figure out why we were getting so many calls," said Palladino, operations manager for S. Zitner Co., a $2 million business that has been around since the 1920s. "We haven't really been able to get to the bottom to analyze it."

Customers surely want to know.

"Candy people seem to get very frustrated, sometimes hostile," Palladino said, with a chuckle. "It's almost like I should be delivering it to their house."

Zitner's eggs hit store shelves after Valentine's Day in some of the region's largest supermarkets. There was plenty to start the roughly five-week Easter shopping season, Palladino said.

Retailers often base a year's order on how much sold the prior year. Last year's Easter shopping season was shorter because the holiday landed earlier. But Palladino said many retailers seemed to put in big-enough orders this year to adjust.

So the explanation for the shortages remained elusive last week, he said. An official at a Wal-Mart store in Marlton told Palladino that Zitner's candy did better than the competition.

"She was saying that - she didn't mention other names - 'We had tons of candy left over, but yours was off the shelf a week before Easter,' " Palladino said. "They took a big order in."

Indeed, part of the company's strong sales this year was the result of greater interest from Wal-Mart, said broker Morton Gleit, 73, of Eisman Gleit Four Star in Bridgeport, Montgomery County. Gleit sells Zitner's candy wholesale to retailers large and small, supermarket chains and mom-and-pop stores, too.

Gleit sold Zitner's candy to about 30 Wal-Mart stores this year, compared with just under 20 the year before, he said.

As supermarket chains heard Wal-Mart was expanding its Zitner reach, they, too, either beefed up their stock or got back into the Zitner game after, say, a few years of leaving them off their shelves, Gleit said.

The candy was selling so well at one Wegmans store, Gleit said, that the supermarket placed a reorder about three weeks before Easter.

Many large retailers are reluctant to place new orders close to a holiday, for fear of ending up with unsold merchandise.

Mom-and-pop shops, however, kept the reorders coming and seemed well-stocked, Gleit said.

Susan Smith, a spokeswoman for the National Confectioners Association in Washington, said it was too soon to know how well Easter-candy sales went this year.

"We've had anecdotal reports from some retailers that consumers were determined to celebrate Easter and were doing so with candy," Smith said. Hard numbers will show for sure in about two weeks.

"Candy is not recession-proof," Smith said, "but people still continue to purchase candy."