CREATE TABLE <TN>  and DROP TABLE <TN> metadata commands in runtime. I populate the tables and that's all. I don't create domains, not at all. 

I use FB 3.0 on a Linux server (I don't maintain that server) . 

The database file is very big - 1+ GB in size, my customers append arround 3000 records each day. 

To try to fix my domain name problem I do as you suggested : I do the restore of the new database file with the correct structure and datapump the records. I just did that yesterday (I have some 6 million records in a few tables) but this process is very time consuming - around 4 hours of work. 

I have one possible explanation :  last time I upgraded from FB 2.55 to FB 3.0, I did the process on a Windows machine : backup FB 2.55 and restore FB 3.0 on the machine. I copied , then, the FDB file in Linux (Samba) , didn't performed a normal restore on Linux (because it is very time-consuming and my customer couldn't wait). Maybe something bad happened then with those domain names. Yesterday I did this : 

1. Exported the records (in some XML files) 

2. Restored an empty database file (full restore - not copy the FDB file) 

3. Datapumped the records (from the XML files) . 

I will see the result and keep you informed. 

Thank you , 

Tiberiu