Hellen,

Thanks for your support. I switched thread because I think the error
"Lock manager out of room" was a consequence of "SCH_validate" error.
I apologize and remain in this thread.

You gave me a good hint to solve the problem, as I found the
SCH_validate error in two different servers I have.

Server A:
Pentium III - 300 MHz - 256 MBytes
Fedora Core 2
Kernel 2.6.5-1.358 #1
NPTL 0.61
FirebirdSS-1.5.2.4731-0

Server B:
Pentium IV - 3.0 GHz - 1 GByte.
Debian Etch
Kernel 2.6.18-4-686 #1 SMP
NPTL 2.3.6
firebird2-super-server 1.5.3.4870-12

Clearly, the first one is the case you pointed at, so I'll install
.nptl.rpm packages in Server A

For Server B, I'll ask again the Debian Firebird mantainer if his
package is NTPL or not.
In the case it is not ¿ Should installing the Classic Server package
solves the problem ? ¿ Does using a single processor kernel (not SMP)
to avoid hyperthreading help ?

Thanks again,
Aldo