Sidebar browsing broken since 2.0

Since the move to 2.0, the sidebar browsing is no longer working properly when browsing files hosted on our NAS: when we use the sidebar to dig into a subfolder structure, expanding a directory node often produces no effect: the Triangle icon is pointing down, but no content is shown below it. Only by using the right-click menu > Refresh, does the content appear.

This affects all our Windows 7 configs, when accessing our files via SMB. The files are stored on a dedicated Linux NAS (FreeNAS), on our LAN.

The issue seems to only affect "deep" folder structures, not the first/second levels.

The issue does not seem to affect files stored locally, or shared on a Windows server.

This was working fine up to Build 2181 (remarkably well, in fact!)

The 2.0.1 update does not fix the issue.