Here is the tail of the output of gbaking my database.
I´ve been working on it for the last days, updating it´s
structure. At some point the thing gets unstable, so i
backed up, but when trying to restore i get the following :

... many lines here...
gbak: restoring data for table SECCION
gbak: 1 records restored
gbak: restoring index RDB$PRIMARY90
gbak: restoring index RDB$FOREIGN245
gbak: restoring index RDB$FOREIGN246
gbak: restoring index RDB$PRIMARY89
gbak: restoring index RDB$PRIMARY88
gbak: restoring data for table REGION
gbak: 1 records restored
gbak: restoring index RDB$PRIMARY87
IBE: Arithmetic overflow or division by zero has occurred.
arithmetic exception, numeric overflow, or string truncation.

Is it a data problem ? sturcture problem ?
The gbk is restored to a new gdb, data is recovered up to the
last table (REGION). DDL of tables, procedures, exceptions seems
to be ok. No triggers are restored.
The original gdb contains 143 tables, 38 procedures, 34 generators,
1 exception, 8 triggers and of course, lots of constraints (PK,FK,etc)

Any idea appreciated.

Using Ibexpert with FB 1.02 (WI-V6.2.908) ODS 10.0
server : localhost with local connection.
O/S : WINXP SP1 (512MB RAM)