Twitter users should refrain from changing their log-in data until further notice or else risk getting locked out of their accounts.
Twitter is investigating instances of users who have lost access to their accounts after modifying their usernames, passwords or e-mail addresses, the microblogging company said on Tuesday.
Until the problem is resolved, Twitter users shouldn't modify their log-in data, according to an official posting on Twitter's Status Web site.
"This seems to affect new users as well as long term users," the note reads.
Users first started reporting the problem late last week, according to messages posted on the site's Known Issues section.
Twitter has made the fixing of this problem a top priority, and at the moment believes the cause might be a caching bug somewhere in its systems, according to information on the Known Issues page.
This is the latest technical hiccup that has affected Twitter in recent days. On Monday, the company acknowledged that the site experienced increased system errors and that users had trouble authoring and posting messages. The latter issue apparently remains outstanding. Last week, a bug caused a delay of several hours in updates to users' message streams.
Twitter, a social network and microblogging site, has become tremendously popular among individuals and organizations since its launch in March 2006, but along the way has earned a reputation for having wobbly performance and uptime.
Twitter experienced lengthy and frequent system outages in 2007 and during the first half of 2008, but since then the situation has improved.
Twitter ended 2008 with 84 hours of downtime, which gave it an uptime frequency of 99.04 percent, the worst among 15 major social-networking services reviewed by Web monitoring company Pingdom.
At Twitter, individuals provide real-time updates about themselves, while organizations use it as a marketing tool. Twitter messages cant' be longer than 140 characters.