By John Dodge

CHICAGO (CBS) — Perhaps the Hamburglar has a thing for mozzarella, too?

That might be one theory following customer reports of cheese-less mozzarella sticks from McDonald’s. While a McDonald’s official acknowledges the problem, she said the issue was not widespread.

Starting late last year, and continuing into January, customers have been taking to Twitter, wondering “where’s the cheese?”

In many of the photos, it appears that the cheese congealed onto the sides of breading during the baking process. In others, it looks like the cheese was never even there.

However, this customer in Texas got just want one would expect.

A McDonald’s spokeswoman apologized.

“We are aware of a low volume of guest concerns about our Mozzarella Cheese Sticks,” spokeswoman Lisa McComb said. “In these instances, we believe the cheese melted out during the baking process in our kitchens and shouldn’t have been served. We apologize to any customers who may have been affected. We are working to fix this in our restaurants.”

McComb added that the company serves about 25 million customers a day and the number of complaints about cheese-less mozzarella sticks is “extremely low.”

CBS Chicago purchased two orders on Friday at a downtown Chicago store.

All of them contained cheese.

After testing the appetizer in some markets last year, McDonald’s began selling the sticks (3 for $1) nationwide this year.