I havent used it for a long time Whiskas,but I found this from an old thread :
Incredimail stores the info in the following directory
Incredimail | Data | Identities | {xxx strange number xxx} | Address ..... or Messages
If you find that folder and then tell incredimail to import the address book from there it may sort your problem out
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Cant understand why it was ok at first though and messed up after a few days
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