Using FTM on two computers sync'd to onlline tree

Hi – I am using FTM 2012 on my desktop computer and have published my tree on Ancestry.com as a Public Tree.I use Tree Sync to keep both trees updated.I would now like to install FTM 2012 on my laptop, download my tree from Ancestry.com and then use Tree Sync to keep everything in sync.

I have installed FTM 2012 on the laptop and updated it.When I try to download my tree from Ancestry.com, it shows as “no action available”.What am I doing wrong or is there a better way?

Thx in advance - Tom