Martin,
I cannot reproduce this problem so I guess I need more info from you.
What are your IPTC/XMP prefs set to? Perhaps you could post a screen capture of the section "For TIFF-based RAW photos" or just let me know whether you have "Add embeded IPTC" and "Add embeded IPTC4XMP" checked, and what the menu setting is for XMP sidecar files. Also, what is your Default IPTC encoding set to (e.g. Mac Roman) and are you writing IPTC as Unicode? If you are only embedding IPTC and you are using Unicode, please be aware that Photoshop cannot properly read Unicode (UTF-8) IPTC data.
By address do you mean the Contact Address field?
--dennis