C:\Users\"YOUR USER NAME"\AppData\Local\GARMIN_Corp\BaseCamp.exe_Url_urbejbdz42c555ix3xqbitecusqt0tuj\4.5.2.1\user.config
is causing my problem; I have to delete this file EVERY time I want to start BaseCamp.
I have spent an hour or so with the software trouble shooters who lead me to the "fix".
We thought it was going to be a one time evolution, but it turns out I have to delete it every time I start BaseCamp.
This "fix" has also been posted in an other posting. I hope some one comes up with a permanent fix in the near future.