BaseCamp:the track lose information like elevation, and time.

If you want to keep the original information create a duplicate track (right click and select duplicate) then make any changes on the duplicate, not the original.

I was unable to reproduce what your are seeing by erasing or deleting points. I would suggest you back up your data and reinstall BaseCamp from the download site:

http://www8.garmin.com/support/download_details.jsp?id=4435

It's always best to duplicate before editing in case of errors. If you still have problems, you should report it Garmin support. They will have a better chance of finding and fixing the problem if you can provide a track and instructions on what exactly you that can be reproduced.

OP is correct..... I't a B-U-G BUG BUG BUG

I was unable to reproduce what your are seeing by erasing or deleting points. I would suggest you back up your data and reinstall BaseCamp from the download site:

http://www8.garmin.com/support/download_details.jsp?id=4435

It's always best to duplicate before editing in case of errors. If you still have problems, you should report it Garmin support. They will have a better chance of finding and fixing the problem if you can provide a track and instructions on what exactly you that can be reproduced.

Its a bug, plain and simple. I've been struggling with the same thing EXACTLY as described by the OP..... No reinstall is going to fix this.
More info here: https://forums.garmin.com/showthread.php?62024-BaseCamp-4-2-4-is-now-available (Bug info begins at post #20)

Also here:
https://forums.garmin.com/showthread.php?63534-No-quot-On-The-Trail-quot-forum-Firmware-Suggestion-amp-BUG-Update&p=230072#post230072

I'm now beginning to think it may be related to to renaming the data when an error is encountered (like the name already exists and an error is returned.) Or it may have something to do with multiple "instances" of the same data in different lists/directories. Also, directory hierarchy does not always properly display all data in sub-folders/sub-lists until Basecamp is closed and re-opened. (You can sometimes see the data in the list, and in the list's parent directory, but not when clicking on a directory higher up etc.....

Basecamp has grown into a a quite capable product. Needs a bit more "refinement" and find these deeply routed "bugs." ~ Progress with Basecamp is apparent, and as version 5 approaches, I think/hope they'll be there.........

PS: Duplication/editing the duplicate does seem to be the only solution to avoid this data loss.... (Unit I'm using is a Montana 650 so this is obviously an issue with Basecamp and not GPS firmware.) Unfortunately, Garmin has not delivered an elegant "sync" solution in Basecamp to help manage data & avoid redundancy. This makes it very difficult as data grows. Their auto renaming is not consistent between data types (ie. waypoints and tracks). And the firmware issues on the units just make this sync problem worse.

If Basecamp could somehow differentiate between archived tracks and "favorites" on the GPS unit, that would help. (To accomplish this in Basecamp all that would be needed is: A display of the folder directory structure of the GPS unit when connected.) ~ At present Basecamp shows all the data (with the exception of Adventures) combined without any directory info.