Highlighting

Hello,
I am running OS 10.3.2, Mozilla 1.6.
A couple of months ago, on using Netscape 7.1, wrote to Moz. champ. 
about highlighting (color, underline, bold) disappearing in my received 
messages as well as in my copies of sent mail in Sent folder. This was 
not really resolved, or only temporarily (was using earlier OS 10 
version at that time). Now the problem persists; an underlined word will 
appear with a single underlined space immediately before and after the 
word, and a bold word will have an asterisk before and after the word, 
with the asterisk after the word sometimes being one space removed from 
the bolded word. Further, color highlighting also disappears. I also use 
Japanese, and I have switched the character coding to Japanese and typed 
English, but there is no change. I have experimented with different 
fonts, but to no avail.
I also sometimes have what I call a 'lag problem', when I type within 
the e-mail message pane, and hit the space bar, but no space will be 
created until I type the first letter of the next word. Strange!
I have checked my prefs again and again.
Could this be an OSX problem, or perhaps keyboard-related?
Arndt Gerz