This happens when I use Sculptor too. I have no idea of the thinking behind it, hopefully someone will clear that up. It means that every Sculptor menu has to be edited before uploading.
You will need to open one of your pages (other than the index page) and re-enter the menuwriter interface to add the link to the home page. You do this by:
In the properties panel at the bottom of the page the menu edit items should be displaying. Click on the middle one - 'Edit contents'. [image 2].
Highlight the top item 'Home Page' and click the plus (+) button above the window, and select 'static link'. [image 3]. Name it 'Home' (or whatever you want) and link it to index.php [image 4]. With the new link highlighted in the list, use the 'up' arrow to move it to the top of the list. [image 5].
Click OK and OK again to finish.