Twitter is having trouble again with a digital certificate that secures communications to its Web site, which has been causing trouble for third-party applications that integrate with it, but the problem may have been fixed.

Some users have reported trouble in using TweetDeck, an application used to post messages to Twitter and organize other streams of messages from the microblogging service. Users see a message saying that a SSL (Secure Sockets Layer) certificate issued by Equifax to "*.twitter.com" has expired and/or is invalid.

The certificate apparently expired on Monday and was used for api.twitter.com, which is used by third-party applications to exchange data with the service. Later in the day on Monday, it appeared the certificate had been renewed, with a new expiry date of Aug. 15, 2011.

More: http://www.pcworld.com/article/201980/