When I use database in ODS 11.1 with several procedures with parameters and I try to run such SQL:

select p.rdb$parameter_name,max(p.rdb$procedure_name)
from rdb$procedure_parameters p
group by 1

Server reports:
Arithmetic overflow or division by zero has occurred.
arithmetic exception, numeric overflow, or string truncation.

It's very strange because p.rdb$procedure_name is only 31 chars long.
I mean that is a problem in unicode charsers....