Operating system name and version: Gentoo Linux
Version of smsd: 3.1.14
Smsd installed from: /usr/portage/app-mobilephone/smstools/smstools-3.1.14.ebuild
Name and model of a modem / phone: Huawei E1750
Interface: USB

I am unable to start daemon using standard Gentoo start script. Effective line is start-stop-daemon -b -m \ -p /var/run/smsd/smsd.pid \ -c smsd:sms \ --start \ --exec /usr/bin/smsd -- \ -c /etc/smsd.conf

User & group set in config:
$ egrep "(user|group)" /etc/smsd.conf user = smsd group = sms

After running startup script as root I get the following log:
$ cat /var/log/smsd.log 2011-07-25 17:49:43,2, smsd: Smsd v3.1.14 started. 2011-07-25 17:49:43,2, smsd: Running as smsd:sms. 2011-07-25 17:49:43,7, smsd: Running startup_check (shell): /var/spool/sms/incoming/smsd_script.DiJFOc /tmp/smsd_data.E1FAZB 2011-07-25 17:49:43,7, smsd: Done: startup_check (shell), execution time 0 sec., status: 0 (0) 2011-07-25 17:49:43,4, smsd: File mode creation mask: 022 (0644, rw-r--r--). 2011-07-25 17:49:43,2, smsd: Smsd mainprocess terminated because the pid file /var/run/smsd/smsd.pid cannot be written.

and .pid file $ ls -la /var/run/smsd/ total 12 drwxrwxrwx 2 smsd sms 4096 Jul 25 17:49 . drwxr-xr-x 7 root root 4096 Jul 25 01:22 .. -rw-r--r-- 1 root root 5 Jul 25 17:49 smsd.pid

Anybody has a thought what is wrong in my setup?

It looks like start-stop-daemon creates a .pid file and does not allow smsd to write into it. You could try to use different .pid file for it.

Is there a reason why the script sms3 cannot be used on Gentoo? I think that it should work, and it stops smsd safely, but some other implementations just kill daemon causing broken messages (partially sent or received).