Hi,

I am trying to piece together United award ticket to Europe and noticed something.

Under Multiple destination, I picked the following:
newyork-> madrid 5/6/2014
madrid-> paris 5/9/2014
paris-> london 5/13/2014

There is availability for this. I added one more flight to this. An openjaw/stopover like this.

newyork-> madrid 5/6/2014
madrid-> paris 5/9/2014
paris-> london 5/13/2014
rome to new york 5/27/2014

This shows no availability. I thought there was no availability. So, I tried the following

newyork to rome 5/6/2013
rome to newyork 5/27/2014

So, rome to newyork availability is fine which makes me think that I am not following some rules. I tried looking but could not find what I did wrong, Can someone please explain this to me?

Thanks.