Help .vcf files

[DroidRick]

OK, you have your current contacts .vcf file with tons of contacts (and a backup of it).

You wipe this file completely due to complications on a trip.

You create a second contacts .vcf file and pile up a ton of contacts in it.

Now you would like to do the following: merge the two and also not have any duplicates.
Is there an easy way to do this?

I also have a second question.

I just imported one of my .vcf files. I spent hours and hours getting my groups set up correctly over a period of weeks.
When I imported my .vcf file all of the groups were lost. Why is this? How can I retain my groups?

I am experimenting with Jelly Bean, hence all of these questions.
WTF is going on? I can't add groups for my contacts now unless I sign in to an account online?
WTF ??????


Thanks!