Inconsistencies on various program installations - why do they happen?

[tankman1989]

I usually install Webmin on my Linux servers, usually debian based. I have found that there are A LOT of inconsistencies in the installation process. I can repeat a process 10 times with success, and then the 11th time it won't work. I always use the same ISO for the base install and then run the updates/upgrade, so that is the only variable. The webmin package is the same 1.60 so that shouldn't be causing a problem.

The latest example is the following. I used my tutorial here:
http://www.technibble.com/forums/showthread.php?p=350511#post350511 and when I get to the last step

dpkg –I webmin_1.620_all.deb

This was the result:

root@Serv1:/home/username# dpkg -I webmin_1.620_all.deb
new debian package, version 2.0.
size 21023860 bytes: control archive= 60835 bytes.
211167 bytes, 3784 lines changelog
37 bytes, 2 lines conffiles
1624 bytes, 16 lines control
1810 bytes, 38 lines copyright
2292 bytes, 89 lines * postinst #!/bin/sh
284 bytes, 9 lines * postrm #!/bin/sh
868 bytes, 33 lines * preinst #!/bin/sh
518 bytes, 14 lines * prerm #!/bin/sh
Package: webmin
Version: 1.620
Section: admin
Priority: optional
Architecture: all
Depends: perl, libnet-ssleay-perl, openssl, libauthen-pam-perl, libpam-runtime, libio-pty-perl, apt-show-versions, python
Pre-Depends: perl
Installed-Size: 130940
Maintainer: Jamie Cameron <jcameron@webmin.com>
Provides: webmin
Replaces: webmin-adsl, webmin-apache, webmin-bandwidth, webmin-bind, webmin-burner, webmin-cfengine, webmin-cluster, webmin-core, webmin-cpan, webmin-dhcpd, webmin-exim, webmin-exports, webmin-fetchmail, webmin-firewall, webmin-freeswan, webmin-frox, webmin-fsdump, webmin-grub, webmin-heartbeat, webmin-htaccess, webmin-inetd, webmin-jabber, webmin-ldap-netgroups, webmin-ldap-user-simple, webmin-ldap-useradmin, webmin-lilo, webmin-logrotate, webmin-lpadmin, webmin-lvm, webmin-mailboxes, webmin-mon, webmin-mysql, webmin-nis, webmin-openslp, webmin-postfix, webmin-postgresql, webmin-ppp, webmin-pptp-client, webmin-pptp-server, webmin-procmail, webmin-proftpd, webmin-pserver, webmin-quota, webmin-samba, webmin-sarg, webmin-sendmail, webmin-shorewall, webmin-slbackup, webmin-smart-status, webmin-snort, webmin-software, webmin-spamassassin, webmin-squid, webmin-sshd, webmin-status, webmin-stunnel, webmin-updown, webmin-usermin, webmin-vgetty, webmin-webalizer, webmin-wuftpd, webmin-wvdial, webmin-xinetd
Description: web-based administration interface for Unix systems
Using Webmin you can configure DNS, Samba, NFS, local/remote filesystems
and more using your web browser. After installation, enter the URL
https://localhost:10000/ into your browser and login as root with your root
password.

It didn't say it installed and it didn't say it failed, but going to the URL to access it, failed. So I looked for some other examples and came up with this:

dpkg --install web*

Which isn't really different than the previous command which I tried a variant of

dpkg -I web*

which didn't work either. I don't know why the -I and --install have changed as the -I worked for about 6 months of my use. The following is the result of the last bit of code I tried.

root@Serv1:/home/username# dpkg --install web*
Selecting previously unselected package webmin.
(Reading database ... 51043 files and directories currently installed.)
Unpacking webmin (from webmin_1.620_all.deb) ...
Setting up webmin (1.620) ...
Webmin install complete. You can now login to https://Serv1:10000/
as root with your root password, or as any user who can use sudo
to run commands as root.
Processing triggers for ureadahead ...
ureadahead will be reprofiled on next reboot
root@Serv1:/home/username#

I tried the URL this time and it worked. I have found about 15 tutorials of various ways to install webmin and the author all claim that they have worked for them, but when I try them myself they don't. They were all for the same version of Ubuntu 12.04.1 then running the upgrade. Some can just run

sudo apt-get update
sudo apt-get install webmin

and it works for them! It seems so simple for some, but others have to take 5-15 steps. I just can't make sense of it, and I can't understand how my original tutorial worked for so many tries and then just stopped working.

Does anyone have any insight on this. This is one of the major issues stopping me from using Linux as my main OS.