I've been checking all the posts that come up when searching for petstruct for the past week; and never found any solution to the problem; even though I had tried several files on SuedeWorthey's webserver.
Belfedia, I saw your post today and you mentioned the zoneupdate.zip file; which made me go looking for an update file on the webserver (I found a update_zone.rar file); it contained a zone.exe, zonedebug.exe, and a zoneperl.exe ...
Copied it over and let my client sit in neriakb for about 30 minutes; didn't see any petstruc errors at all
So try the update_zone.rar file drognir, it fixed my problem with petstruct errors anyway.