> It's stated on Firebird's developer documentation ( http://www.firebirdsql.org/dotnetfirebird/transaction-isolation-
> levels.html ) that ANSI/ISO Read Uncommitted isolation level (dirty
> read) was not supported and Firebird's ReadUncommitted level behaves
> like ReadCommitted on Oracle and MSSQL. Firebird's ReadCommitted level
> waits for uncommitted transactions to complete.
> I have an application running via OLDB (LCPI.IBProvider). What I need
> is exaclty ReadUncommitted isolation level (of Firebird) but when I
> choose that option providers says that level is not supported. Is that
> a provider problem or Firebird's?

Since Firebird does not support ReadUncommitted, obviously provider can't support it too.

> Or is there a way to stop waiting
> for uncommitted transactions.

Yes, instead of
READ COMMITTED NO RECORD_VERSION
use
READ COMMITTED RECORD_VERSION

Ivan.