No matter how hard I try, everytime I flash I get duplicates!

[supdawg]

I am so annoyed! Every time I flash a new version of a ROM, I always recreate my contacts and appointments through Myphone.

The problem I run into is everytime I connect my phone to my desktop and try to get it sync'd through AS, I get duplicated contacts and or appointments.

I've tried to set up AS to replace items on my desktop instead of my phone, and it still duplicates them.

What am I doing wrong here?