I downloaded the test version yesterday and played around with this very nice editor. It works very well, however, layout options appear to be broken for me. If I switch from Single Pane View to any other option the document area gets black and the tabs on the top disappear. Sidebar stays visible and according to the status bar the documents are still open and I can navigate through them but I can't see anything of the open document(s).
My specs are: Ubuntu 10.10 64bit.
Some other notes:
+ I installed today's update but no change.
+ Tried the windows version in a VM and layout options work just fine.