Unable to select 'following' for phone updates on web

The 'Follow by phone' icon is not appearing on my Following page. Means that I have to follow by phone using the phone commands. It works with one account and not two other accounts that I use.
This appeared to be reported in April http://twitter.zendesk.com/forums/31935/entries/31933 and the subject line includes 'Fixed' but doesn't seem to be the case.