Randomly formatting text

I have text in a word document. I paste it into a .txt file to remove the formatting, which is does. I paste it in to the WordPress page and it is fine. I save it and it randomly puts words that are capitalised in Bold. I strip it out it puts it back.

I am on the latest version of WordPress.

I have tried:
Taking the plain text in to an HTML editor and then pasting that in way
pasting from word option
pasting form txt option
I have tried remove formatting option

This works until I save and then it puts the bold text back
I have disabled WordPress should correct invalidly nested XHTML automatically
I have tried firefox and I.E.

Please help before my laptop goes out the window