Description of problem:
When configuring partitions by myself, I am able to add multiple partitions to mount to same mountpoint. If I do, only the latest created partition is displayed, but the remaining free size is displayed correctly. If I delete one partition, it remains there (the last but one is displayed) and so one.

How reproducible:
Always.

Steps to Reproduce:
1. Try to create partitions by yourself
2. Add more partitions, write same mountpoint.
  
Actual results:
UI lets user to to that, only one (latest) partition is displayed.

Expected results:
UI shouldn't let user to do that, there should be some kind of warning or, at least, it should display all partitions.