At 10:39 PM 5/10/2006, you wrote:

>By the way: IBO version is 4.2.Ib and Firebird version is 1.5.0.4290 (Linux).

This is probably the most USEFUL piece of information about your
problem. In short, that (very, very old) version of IBO is not
compatible with the default settings in Firebird 1.5, which corrected
an old Interbase and Fb 1.0 bug. It's such an old issue, I'd
practically forgotten about it. You need to either upgrade IBO to
v.4.3Aa or higher, or set the OldParameterOrdering property in
firebird.conf to 1 (and uncomment it, of course).

OldParameterOrdering is *not* meant to be a permanent solution,
merely an accommodation at the time, to make the transition less
disruptive for IBO developers. It makes any databases on your server
prone to unpredictable wrong results if accessed with anything
*other* than those very ancient IBO versions.

Helen