Computer users looking to log on were presented with a message telling them to upgrade their software to connect, although no newer version of the software was available.
A StreamCast spokeswoman confirmed that the network was temporarily inaccessible to many people, citing "technical issues," but she did not give any details. She gave no estimate on when a fix would be available.
Morpheus is built on peer-to-peer technology that allows people to connect directly with each other's computers to trade files--an architecture that has been touted as impervious to the kind of court order that shut down predecessor Napster.
Morpheus uses software originally created by a group of Dutch developers at FastTrack that also powers rival Kazaa. That file-swapping network, which was recently acquired by Australia's Sharman Networks, appeared to be functioning normally Tuesday. A new version of Kazaa was released Feb. 11.
StreamCast, along with Kazaa and Grokster, is being sued in Los Angeles federal court by the big record labels and movie studios, which contend the services are contributing to widespread copyright infringement. The two sides are scheduled to meet in court March 4.