Keyboard not working *correctly* in command-line interfaces

So, I've been dealing with a bit of an annoyingly bedeviling problem for the last few days, and the symptoms are so weird that it's difficult to search for people who are having the same problem - so I figured I'd post here and pray someone has had the same problem and has figured out how to fix it.

The Problem: 

Basically the keyboard does not work correctly in a command line interface - the moment you type any key it starts thinking that you're holding down one different key on the keyboard.  The annoying thing is that the keyboard works correctly at all other times.  

The Machine:

I'm using a Dell Latitude E5520.  This laptop is maybe about a year old.  As for what software is being used, I'll explain the details next.  

What I've done:

So, the first time I encountered this problem was was after installing encryption software on the laptop - I'm using TrueCrypt (http://www.truecrypt.org/) to encrypt the laptop harddrive with a standard windows XP install.  Truecrypt is pretty simple to use: you install it, give it a key and it encrypt the drive, and it'll load before the OS, prompting for a password - you type in the right password and it loads the OS.  With this computer though, I was unable to actually give it a key because the moment you pressed any key on the keyboard it acted like a key was being held down on the keyboard.  

Now, the keyboard worked perfectly fine in the bios (which on this computer runs in it's own little gui), and if you pressed esc while in truecrypt (because a key had not yet been set) it would load XP, where the keyboard worked perfectly.  Additionally, it *seems* to work correctly when selecting a boot option - but if someone was holding down a random key on the keyboard at that point in time chances are good it wouldn't affect anything anyways.  

So, I figured that it's probably a problem with the software - completely reformatted the hard drive and re-installed everything.  No luck.  I then figured that it might be a hardware issue, so I tried swapping out the keyboard (didn't work) and the motherboard (didn't work) and the memory (didn't work) and flashing the bios (didn't work.)  When none of that worked, I took the harddrive out of the computer, put it into an identical one, which has the exact same bios settings, and the keyboard worked correctly in truecrypt!  How's that for annoying?  Also, just as an FYI, I did run the dell diagnostic software on this machine, but there were no issues discovered.  

After all of this, I decided on a whim to load lubuntu (https://help.ubuntu.com/community/Lubuntu/GetLubuntu) onto my flash drive and see if I might find something useful by booting off of it.  There, if I tried entering Command Line Interface (CTRL+ALT+F1 for example), immediately it would act like I was holding down the ~ on the keyboard.  I then loaded DOS onto my flashdrive, booted off of it again, and found the exact same thing, except once I pressed any key on the keyboard it would act like I was holding down the c key.  

To throw another lovely wrench in the works, this problem only happens when using the laptop's integrated keyboard.  This will not happen if I use a USB keyboard instead.  

In Summary:

So, the keyboard acts like a specific, random key is being held down in any CLI - but not in any other interface - and after replacing all the hardware and software involved I still have absolutely no idea why.  If anyone can held me out with this I would be incredibly grateful.  Thanks!