Ciao Muhammad,
I'd use CentOS 6, or Debian Squeeze.
That said, follow carefully all the steps, install the prerequisites, and use the installer.pl
Other comments are below, between your lines
[root@FreeSwitch install]# sh /usr/local/freeswitch/skypopen/skype-clients-startup-dir/start_skype_clients.sh
ERROR: Module snd_pcm_oss does not exist in /proc/modules
ERROR: Module snd_mixer_oss does not exist in /proc/modules
ERROR: Module snd_seq_oss does not exist in /proc/modules
mknod: `/dev/dsp': File exists
insmod: error inserting '/usr/local/freeswitch/skypopen/skypopen-sound-driver-dir/skypopen.ko': -1 File exists
Fatal server error:
Server is already active for display 101
If this server is no longer running, remove /tmp/.X101-lock
and start again.
bash: /usr/local/freeswitch/skypopen/skype-clients-symlinks-dir/skype101: No such file or directory