[Groff] Underlining wierdness question

[Clarke Echols]

I'm working on a document with a headline:

    Are You Sure You're Getting Maximum Value

where the line is set in Helvetica bold with "Sure" set in
HB italic.  I want to underline the word "Sure", but I'm getting
strange behavior from what I thought should be a legitimate approach.

Conditions are:
   .ll 6.5i
   .ps 12
   .vs 14

My strategy was to set the font to HB, set the first two words, then
switch to HBI for word "Sure".  After setting that word and going
back to HB, I then do a horizontal move left 0.55i, move down
2.5p, use \D escape to draw a line with thickness 2000 units, .55i
in length, back up 2.5p, and do the rest of the line.

But I get a strange behavior.  groff draws the line as I want,
but it somehow injects a line about 30 points long (.41 inch long),
even if I disable the line drawing \D escape sequence.

The first line below is what I used to kill the line draw, but
it still gives a short line.  The second line gives me what I want,
but I still have the short line and don't have a clue what's causing
it.  I'm running groff 1.18.1 under cygwin.  The two lines lie directly
one on top of the other.

[EOL] is a space character in each line that was followed with an
end-of-line for the email program to keep the lines readable.  In the
actual file, it's all one line with the same characters except [EOL].

> .ce1
> \s+6\f(HBAre You \f[HBI]Sure\fP\h'-0.55i'\v'2.5p'\D't [EOL]
> 2000'\h'.55i'\v'-2.5p' You're Getting Maximum Value

> .ce 1
> \s+6\f(HBAre You \f[HBI]Sure\fP\h'-0.55i'\v'2.5p'\D't [EOL]
> 2000'\D'l .55i 0'\v'-2.5p' You're Getting Maximum Value

Do any of you groff geniuses have a clue about what's going on
here?  I don't see what could be causing it.  I can live with
what I have, but I'd rather drop the line 3p instead of 2.5
which is where groff puts it, no matter what the \v escape
tells it to do.

Thanks,

Clarke