warmonger, i agree i don't see why "minusminus" inside a comment, and not followed by "greaterthan" shouldn't be condidered as the end of the comment. Probably due to some historical reasons (maybe the first w3c validator used to have this "bug" and they decided to make it part of the spec...).
Anyway, in the current case, each time someone quotes someone else, it create an incorrect comment, and Mozilla decides that the comment last until it encounters ANOTHER misconstructed comment. see, using mozilla, the "view source" on http://forums.storagereview.net/index.php?...showtopic=11152 for a good example:
Mozilla apparently decides to 'ignore' the "minus minus", preceded or not by a SPACE, and followed or not by a "greaterthan", until it encounters ANOTHER misconstructed comment, such as another QUOTE. It then chooses to consider the "comment" finished.
The result is that is in a post "userA" and then "userB" both quote someone, mozilla will display the CONTENT of the post of "userB" in front of the name of "userA" ! and none of what was in between (content of the post of UserA included).
Very disturbing, but perfectly normal as a program that encouter a syntactic error is allowed to go into an "unspecified" state and do basically whatever it wants (or can) do. The fault lies into using those incorrect "minusminus inside a comment" contruction, not in the rendered (mozilla here, and possibly some other browsers).
What a browser will do when it enconters such things is up to the program, and can't be relied on or doesn't have to make sense. (a good read for what happens to, for example, a C compiler that go into a undefined sttate is : http://www.lysator.liu.se/c/c-faq/c-faq-toc.html , question 4.2)
The fix should be as 'easy' as modifying the forum-software source so that it doesn't use "minusminus" as a separator inside a comment, but uses instead " - " or whatever seems appropriate.
Hope this helps,