I think you misunderstood my suggestion.
When you reply, just put your reply 'below' the previous person. Not in
a new message all together.
See above. I put a string of text in caps 'inside your message'.
The string in caps looks like its part of your message and it isn't.
Its confusing to others. I think that is all I was trying to point out.
In most readers you see the vertical bars on the side of other posters
or you see > characters beside their text etc.
If you're not using a news reader like Outlook or Thunderbird or Agent,
you might want to try one of those. They are made to read and track
threads in a subject a bit better than other methods.
Good luck. No harm done.