Strange Keyboard Problems

So I have an Inspirton 640m and an Inspiron 1405, practically two of the same. Here's my problem:

My dog decided to mark his territory on my laptop (the dog later regretted it), however upon examining the insides, it seems the only thing that had gotten wet was the keyboard, however it still worked (for the most part.) The 1405 is in pretty bad shape, so I decided to swap the keyboards.

Now for the strange events: all keys works, however some combinations do not. Left Control + Backspace does not delete a word, however both DO work independently. Something I've noticed is that when typing the word "not", it will often come out as "ont". The space is still being held when pressing the letter "N",  and by the time the letter "O" is pressed, I've released the spacebar, however, the "N" is still being pressed, so it comes out at "on" and by that time the "T" is pressed, so it becomes "ont." Again, all keys work perfectly independently.

I should mention that the 640m was purchased in Australia, while the 1405 was bought here in the States. The keyboard are definitely different (i.e. different model numbers, and *very slightly* different looking cables, but they both fit), so I'm wondering if this is the cause of the issue.

Also, when I boot the computer up, at times it will beep (as if I'm pressing a key) until I press ANY key to get it to stop. (This was a bad thing while installing XP again as it kept activating the install disc.)

Any help would be appreciated!