Resolved Category contacts

Greetings All,
Copied my contacts/category list from main computer to laptop. On laptop sending an email to a group worked fine until I closed program. Upon re-opening Win Live Mail contacts showed in groups but were not recognized when trying to send. Created a new category and moved contacts to that enabled me to send to group. Closing mail program and re -opening resulted in same problem. Moving contacts back to original cat enabled me to send email to group. Closing program resulted in same problem.
How do I get WinLiveMail to remember contacts in specific categories?
Assistance appreciated.
Stephen