The new version of the Beta is available at http://developer.garmin.com/apps/BC/BaseCampBeta_4.2.0.2.exe.
This version should fix the issue of folders and lists disappearing. If you already ran 4.2.0.1 please use "Restore from previous version" to re-import the 4.1 data with lists and folders intact.
As with all Betas, this is a preview of our next feature release. There will be some rough edges, so make sure you back-up your data before using it.
We are looking for feedback regarding the new features, please let us know what issues you encountered with functionality and usability. Please report any crashes you see, with steps to reproduce if possible.
I compiled some screen-shots of the new stuff at https://forums.garmin.com/showthread.php?36044-What-s-new-in-BaseCamp-4-2.
The rough list of changes:
Added Trip Planner (work-in-progress)
-adds easy way to create trips
-create trips over several days
-round trip support
-printing trips
-add destinations along the route
-flying support (airport and flight look-up)
-time zone support
Added support for different route profiles for different legs of a route
Added support to have different folders and lists with the same name (as long as they have a different parent in the folder hierarchy)
Added support for UK postal code search
Added support for Yelp search (work-in-progress)
Added support for named search (far away POIs should be found if it's an exact name match)
Added support for category search (you can type "Hotels, Las Vegas, NV")
Added quick search (hover over the map to invoke it)
Added Irish Transverse Mercator grid
Added support for displaying BirdsEye while in Basestation mode
Added support for displaying and saving the track of the Basestation itself
Added support for displaying the most recent update time for Basestation contacts
Fixed issue with Garmap Southern Africa Topo & Rec 2012.3 - NT not being displayed BaseCamp