i'v now changed it using "is null rather than =0
so...
[x]=Trim([Home Address]) & IIf(Len(Trim([Home Address])) Is Null,"",Chr(13)) & Trim([Address]) & IIf(Len(Trim([Address])) Is Null,"",Chr(13)) & Trim([City]) & IIf(Len(Trim([City])) Is Null,"",Chr(13)) & Trim([State]) & IIf(Len(Trim([State])) Is Null,"",Chr(13)) & Trim([Zip/Postal Code]) & IIf(Len(Trim([Country])) Is Null,"",Chr(13)) & Trim([Zip/Postal Code]) & [Country]