From: http://parekhreena.blogspot.com

Facebook not showing All updates of your Friends ? Here’s how you can solve the problem

Wondering why you didn’t see that image/status from your friend on your News Feed ? Here’s the answer:

When the Facebook Smart Lists & Timeline were introduced, these changes affected the News Feed too. Facebook now comes with an option to view 3 types of updates from your friends:
  1. All Updates
  2. Most Updates
  3. Only Important Updates
All Updates – This will be selected automatically if you have listed the friend in your “Close Friends” list. “All Updates” will show you every single update from your friend, including the third-party posts they like/comment, their game updates, etc. Clearly, this is nothing but a headache if your friend is too active on Facebook.
Most Updates – This is selected By Default for all your friends(Except ofcourse your Close Friends) and is the main Culprit why you miss some of the updates from your friends.
 
Only Important – This includes life-events, photos and popular statuses. Popular Status is a status from your friend which has got many likes and/or comments.
There are 2 ways to solve this problem: