font-lock doesn't mark block comments as "multiline"

[Chris Page]

I'm the maintainer of Dylan mode for emacs (see my .sig). Like C++, 
Dylan has both "end of line" comments beginning with "//" and block 
comments surrounded by "/* ... */".

Although font-lock automatically applies the comment face to block 
comments when they're defined in the character syntax table, when I edit 
text within a block comment, it loses the comment face and is fontified 
as though it were not within a comment.

There are several ways I can imagine fixing this, but I'm wondering why 
font-lock doesn't automatically apply the font-lock-multiline property 
to block comments when it's applying the face to them.

Is there some other, recommended solution?

-- 
Chris Page - Dylan Programmer

 Open Source Dylan: <http://www.opendylan.org/>
    Dylan Blogging: <http://homepage.mac.com/chrispage/iblog/>
       Dylan Stuff: <http://cafepress.com/chrispage>