I was right arrowing through my english bible parallel resource and B4 threw a fatal exception.
0451.Logos4.zip">http://community.logos.com/cfs-file.ashx/__key/CommunityServer.Discussions.Components.Files/78/0451.Logos4.zip:550:0]
On the whole I have had more crashed with B4 than any other Beta, although I have been having a hard time defining the steps that reproduce them. It just seems fragile.
This bug looks like a problem with the reverse interlinear pane; we'll investigate further.
This should be fixed in the next beta.