Hi Adam, thanks for the reply.
I tried again with a simple import as you suggested, and it worked. I then tried my initial import (with a few minor tweaks) with about 70 contact records, and it worked.
I did 3 things differently for the successful import:
#1 I had a field in the csv file that I didn't use in my first attempt. I assigned that field value manually the first time. In the successful import (the second time) I mapped the field.
#2 The first time I named the checkbox fields with numbers. So in the first line of the file, those fields names were 1,2,3... in the successful import I renamed the fields book1,book2,book3 etc.
#3 In the unsuccessful attempt, I had spaces in the field names. The first line of the import file was First Name,Last Name, etc. In the successful import, the first line of the import file was First_Name,Last_Name, etc.
Thanks for following up with me on this, and I hope this helps others.
And thanks for the amazing software!
Paul