The popular social-networking site MySpace.com suffered a pair of extended outages over the weekend because of power problems at a key data center in the Los Angeles area, the company said Monday.

In a message to MySpace users, company co-founder and President Tom Anderson said MySpace "has been screwy" since Saturday because of failures in both the main power supply and the backup generators. Visitors to the site were given an opportunity to play Pac-Man while waiting for the restoration of their personal profile pages.

The company blamed a heat wave that has gripped California in recent days, increasing electricity demand and leaving tens of thousands of customers in Southern California without power.

The first outage at MySpace started about 8:40 p.m. EDT Saturday and lasted more than six hours. The second began about 9:30 p.m. Sunday and continued until 9 a.m. Monday.

MySpace said that power has been restored and that the site is back up, although the company warned that sporadic outages were still possible Monday.

According to Netcraft Ltd., a British company that monitors Web site performance, MySpace was completely offline for about 90 minutes Sunday. The rest of the time, profiles were inaccessible as MySpace had a temporary page with the Pac-Man game and an outage announcement, which Netcraft said came from another data center in Tempe, Ariz.

"It's unusual to see an outage like this where the systems that were in place clearly didn't work as intended," Netcraft analyst Rich Miller said. "I'm sure they will be looking very closely at what happened to try to prevent it from happening again."

MySpace said it was exploring ways to prevent a recurrence.

Driven largely by word of mouth, MySpace has rapidly risen to become the second-busiest site in the United States, behind Yahoo Inc., according to comScore Media Metrix. MySpace's 96 million registered users can expand their circles of friends through profile pages, photo sharing and other tools provided by the free, ad-supported site.

News Corp. bought MySpace's parent company last year for $580 million as part of its strategy for expanding into the digital world. Over the past several months, MySpace has added instant messaging, video and other features typically offered at Internet portals such as Yahoo.