Why will one specific twitter user's tweets not get sent to my phone?

[Katy]

I get specific tweets sent as text messages. While I follow about 30 people, I only get 5 people's tweets specifically sent to my phone. Over the past week, I've noticed when one of these users tweets it does NOT get sent to my phone. All of the people I have sent to my phone are celebrities, and I know the person didn't block me or anything like that, but every they tweet it doesn't get sent to me at all even though my account says I'm supposed to get notifications from them. Help?

[Intrépïd]

Are you only getting top tweets? Change it to receive ALL tweets.