Error when creating column in MOSS 2007 list

Our MOSS 2007 environment which I have being implementing has being functioning without problems for the last 4 months.  I have created and customised both my own and built-in lists within sharepoint.

I started a new project, I created the custom list and then attempted to create all my columns that I needed.  I entered the column name, the type and left the remaining criteria as default.  I clicked the 'OK' button to create the column, and nothing happens.  I noticed an error symbol in the bottom left corner of internet explorer's status bar, double-clicking it, it displays the following error details:

Line: 804
Char: 4
Error: 'helperFrm' is null or not an object
Code: 0
Url: https://mydomain.tld:port/clients/opportunities/_layout/fldNew.aspx?List=<listID>

I enabled debugging within IE, and tried again, when clicking OK I get this:

A Runtime Error has occured.
Do you wish to Debug?

Line: 803
Error: 'helperFrm' is null or not an object

Now I know that the Runtime Errors in IE are pretty generic, but I allowed the debugging, opening it in Visual Studio 2008 just to see what it came up with.
Visual Studio stated an error on opening:

Microsoft JScript runtime error: 'helperFrm' is null or not an object'
With button options to 'Break', 'Continue', 'Ignore'

I clicked break, and it highlighted the following line of code on the fldNew.aspx page that it opened:

      if(! helperFrm.FValidate(true))



I am not by any means a sharepoint expert, nor a .net or asp expert but I can figure things out very quickly and very easily.  I currently in the processes of learning MOSS and .net.  This is why I need all the assistance I can get.

This problem occurs on every list I have ever previously customised or created, I have tested as much.  I currently have 2 Site collections, each with several sites beneath them.  I have tested on IE6 and 7, on a server 2003 machine, the server 2003 system MOSS is installed on, a XP laptop, a Vista laptop and my personal Vista machine at home.  I have not gone as far to test from a Linux system as I dont have one available.

I have attempted to repair the MOSS installation, but this has not helped.  I have not being able to find a single thing on the internet pertaining to any variation of the errors.

I am very confused and have know idea of where to look next.
Any assistance will be greatly appreciated.