Last night we posted about some ongoing SMS problems. An emergency fix we did last night appeared to address many of the symptoms but we still have problems with SMS commands not being accepted.
We are continuing to work on this.
We are currently working on problems affecting the SMS service for Twitter. Users will notice that Twitter is not responding correctly to commands sent over the SMS service. Also, users are unable to start using the SMS service by adding their device on the web or sending START to the SMS short code.
These are urgent problems and we are working to correct them.
Update (9:35p): These problems have been resolved.
We are expanding availability of Lists to 5 percent of users and will work our way up to a full roll-out in the coming weeks.