I'm using the latest 097 core release (RC5), the problem started when I updated the core version, and yes, I passed the realm correctly. Another thing, we updated our verdata with the change of the core, can it be that the verdata has some problems? (I rebuilt the realms/tile data with uoconvert of course)
I don't know, cause newer versions of UO don't use a verdata.mul anymore. I think uoconvert doesn't use this either.
I suggest using RC4. I haven't had any problems with that release so far. It seems to be a very stable version. At least for me so far