Hello, Marco,
Since some DOA users in JAPAN reported this same ORA-01480 error,
I'm currently investigating this with a small sample program.
With Server:
NLS_CHARACTERSET AL32UTF8
NLS_LENGTH_SEMANTICS BYTE
and Client:
NLS_LANG=JAPANESE_JAPAN.JA16SJISTILDE
I get ORA-01480 when I update a...