I've had the same thing happen (Father and Son got theirs merged). Easiest way to deal with it is to edit the merged contact and select "Separate" from the menu. I've not had a problem with it re-merging the contacts.
Thanks, I looked everywhere for that option before and finally found it.
You can't click on a contact, then go to Menu -> Edit -> Menu -> Separate.
You have to go to the contact, press and hold the name, then choose EDIT, then go to MENU -> SEPARATE.
But, that is still not working for me. I am losing one of the contacts when I do it.
This is probably the most annoying thing about android. I had a Jamie and a Jimmy that got merged without my realizing it, until one of them texted me about a funeral for someone's father. Turns out both of those people and I each knew a seperate "bob" so I spent an hour trying to figure out which Bob's father died and who to call.
Funny, I had a James and a Jamie do the same thing but I was able to delete and re-add one and they stayed separated.
Did you guys try to put a nickname on the nickname box or putting a middle name in the middle name box?
Tried, didn't help.