Help, iTunes duplicates my contacts

[oab]

Ever since I upgraded iTunes to 7.4.3.1, whenever I sync my iPhone it duplicates my contacts both in the phone and Outlook Express. The first time this happened I deleted all of the duplicates both in the phone and Outlook Express. Just synched a while ago to update my iTunes songs and the same thing happened again. This is getting bothersome because it takes over an hour to delete all of the duplicates. Also, it's really strange because not all of the contacts are duplicated only about 80%, and there is no pattern, rime or reason for the order of duplication. Does anyone have a solution for this problem? Thanks much!