Customers trying to track their packages on UPS' website Wednesday were hindered by widespread, intermittent problems that took down some systems at the Sandy Springs company.

Drivers continued to deliver packages, UPS spokesman Norman Black said, but the outages did mean that people had less visibility regarding their deliveries.

A hardware problem was to blame, Black said. He said UPS knew what caused the problem, but that it would take some time to fix. He expected it to be resolved by Wednesday afternoon.

Black said he could not say with certainty that no packages were delayed as a result of the outages, saying that UPS' CampusShip program -- which allows companies to move packages between various campuses -- was affected, meaning some businesses may not have been able to print the labels they needed, delaying their pickups.

At times, he said, UPS.com would time out and would not load.

"It's very rare for something like this to happen," he said. "We did figure out pretty quickly what caused the issue in the first place."

The company handled complaints on Facebook and via Twitter, writing on its Facebook page that it was "treating this problem with urgency."