Errors in WHMCS Installation Script following MySQL database destruction

Hello folks:
The title of my post is well named, and I need to know what you suggest.
Firstly, I had some serious issues in MySQL that required me to take drastic action to be able to log back in as root by erasing /usr/lib/mysql, before I was able to make a dump of the entire database.
though I was then able to recover MySQL at least mostly, no matter what I do with the WHMCS installation script, (even creating) a new virtual host doesn’t help, master admin or not doesn’t help either, it displays the following:

Install Script  

In domain billing.keithnet.us
Found http://software.virtualmin.com:80/download/whmcs_v503.zip in cache ..
Found http://downloads2.ioncube.com:80/loader_downloads/ioncube_loaders_lin_x86.zip in cache ..
Downloading http://www.whmcs.com/members/dl.php?type=d&id=126 (19.67 kB) ..
     Received 1024 bytes (5 %)
     Received 2 kB (10 %)
     Received 4 kB (20 %)
     Received 6 kB (30 %)
     Received 8 kB (40 %)
     Received 10 kB (50 %)
     Received 12 kB (60 %)
     Received 14 kB (71 %)
     Received 16 kB (81 %)
     Received 18 kB (91 %)
     Received 19.67 kB (100 %)
.. download complete.

Configuring webserver PHP settings ..
.. already done.
Now installing WHMCS version 5.0.3 ..


Database connection failed : DBI connect failed : Access denied for user 'khinton'@'localhost' (using password: YES) 1360. 

.. failed! See the error message above for the reason why.

  

So, what does this stuff mean?
I’ve tried checking things from the shell and the usernames in MySQL seem fine, etc.
But what’s going on?
What exactly is this script trying to do in MySQL?
How does it work (without me tryign to teer up the script source code)?
I’m trying to figure out how to resolve this, so that I can begin the long process of setting customers back up.
Oh, and that brings me to problem number two (once HWMCS is isntalled).
I asked WHCMS about this, but just in case Matt and folks refuse to assist, I thought I’d try here anyways.
The trouble is that one of my clients already has a virtualmin virtual Host on the system.
However I do not have a strong grasp of the Virtualmin and WHMCS API to manually add this account into WHMCS (if that’s even possible to do), as I’m afraid that recreating the account in WHMCS will erase all existing Virtual hos details for that client.
I’ve gone and backed up the client’s current home directory just in case so he doesn’t lose any data.
Does anyone have any ideas if recreating the acount for him (assuming I can get passed this WHMCS inability to install) error in MySQL will erase the Virtualmin userID and FileSystem-specific contents stored server-side or not?
Thanks for helping to clarify anything-much appreciated!

Just so you folks know, the khinton user has all privelages granted to billing_whmcs in this specific case. So what gives?

Okay, I tracked the issue down to what I kept entering as a password for the Virtualmin user.
I’m using the encrypted password storage scheme, and that’s good.
However, I kept choosing “encrypted password” instead of “normal password”.
now my DBI error is gone!