NEW YORK – Sony says it has found a bug that has knocked some PlayStation 3 users off the game console's online network.

Sony says the problem was likely caused by a bug in the clock functionality incorporated in the system. It's affecting older PlayStation 3 models, not the newest slim version.

Sony would not say how many users were affected by the problem, which comes just as PlayStation 3 sales are picking up.

Errors that PS3 users started seeing Sunday include the date of the systems being reset to Jan. 1, 2000. The problem was reminiscent of the Y2K bug a decade ago.

Sony said in a blog post Monday it hopes to resolve the problem within 24 hours. But the company warns that certain users should avoid their game consoles until the problem is fixed: 

"If you have a model other than the new slim PS3, we advise that you do not use your PS3 system, as doing so may result in errors in some functionality, such as recording obtained trophies, and not being able to restore certain data."