Hi Denise,
I apologize again for the delay and thanks again for including the relevant files. Your HTML looks good. I tested this and everything displayed properly (although since my set up is different I can't test dynamic content in the same way.)
The only thing I wonder is if maybe the email is not encoding properly? Perhaps you could add the HTML, head, encoding, and body tags and you may see more consistent results.
When you test this to your own internal Lead or Contact do you have real values stored in the appropriate records on your related Account? In the first email, does the code in the subject match the code in the body of the email?
Thanks for your patience as we look into this issue with you.