I have used my 2006 Nutribullet almost everyday and thought it was time to purchase a new one.  I decided to purchase the Nutribullet Pro+ and after using it for the 2nd time I could not remove the top from the base, and I made an awesome shake!  With fluid in the top I could not return it for a refund. 
I sent 2 emails asking what to do and no one responded, best to call.  The customer service rep was awesome and she replaced the unit (but stated it was a user issue - I told her I had a unit that I have used for years with no issues so I know how to use it!   I am afraid it will happen again and have been using my old unit. I noticed someone else had the same issue, so buyer beware!