My Slackware version is 10.1.
Kernel version is 2.4.29.

First time i used the normal (not NPTL) build. Now i removed and
instaled the NPTL build. Just after finish install, there are six
instances of fbserver (threads?) running. It's strange Milan's server
behavior to be different from mine.

root@servidor:/usr/src/FirebirdSS-2.0.0.12710-ReleaseCandidate3.i686#
ps -e | grep fb
root@servidor:/usr/src/FirebirdSS-2.0.0.12710-ReleaseCandidate3.i686#
./install.sh

Firebird super 2.0.0.12710-ReleaseCandidate3.i686 Installation

Press Enter to start installation or ^C to abort
Extracting install data
Starting Firebird server: server has been successfully started
Please enter new password for SYSDBA user: masterkey
Install completed
root@servidor:/usr/src/FirebirdSS-2.0.0.12710-ReleaseCandidate3.i686#
ps -e -f | grep fb
firebird 26210 1 0 22:32 ? 00:00:00
/opt/firebird/bin/fbguard -f -p /var/run/firebird/rc.firebird.pid
firebird 26211 26210 0 22:32 ? 00:00:00 /opt/firebird/bin/fbserver
firebird 26212 26211 0 22:32 ? 00:00:00 /opt/firebird/bin/fbserver
firebird 26215 26212 0 22:32 ? 00:00:00 /opt/firebird/bin/fbserver
firebird 26216 26212 0 22:32 ? 00:00:00 /opt/firebird/bin/fbserver
firebird 26223 26212 0 22:33 ? 00:00:00 /opt/firebird/bin/fbserver
firebird 26224 26212 0 22:33 ? 00:00:00 /opt/firebird/bin/fbserver
root@servidor:/usr/src/FirebirdSS-2.0.0.12710-ReleaseCandidate3.i686#

I tried to stop the server using rc.firebird and it seems it is
working now:

root@servidor:/usr/src/FirebirdSS-2.0.0.12710-ReleaseCandidate3.i686#
/etc/rc.d/rc.firebird stop
Stopping Firebird server:
root@servidor:/usr/src/FirebirdSS-2.0.0.12710-ReleaseCandidate3.i686#
ps -e -f | grep fb
root@servidor:/usr/src/FirebirdSS-2.0.0.12710-ReleaseCandidate3.i686#
/etc/rc.d/rc.firebird start
Starting Firebird server: server has been successfully started
root@servidor:/usr/src/FirebirdSS-2.0.0.12710-ReleaseCandidate3.i686#
ps -e -f | grep fb
firebird 26242 1 0 22:36 ? 00:00:00
/opt/firebird/bin/fbguard -f -p /var/run/firebird/rc.firebird.pid
firebird 26247 26242 0 22:36 ? 00:00:00 /opt/firebird/bin/fbserver
firebird 26249 26247 0 22:36 ? 00:00:00 /opt/firebird/bin/fbserver
firebird 26252 26249 0 22:36 ? 00:00:00 /opt/firebird/bin/fbserver
firebird 26253 26249 0 22:36 ? 00:00:00 /opt/firebird/bin/fbserver
root@servidor:/usr/src/FirebirdSS-2.0.0.12710-ReleaseCandidate3.i686#