How can I force "no splines" in GraphViz html-like labels?

How can I force "no splines" in GraphViz html-like labels?

I am interested in making all of the edges in this graph straight.
From what I understand, setting splines to false should do this.
In one case, an edge has no splines, and goes right over the top of
another node.
In the case of the html-like label, splines appear, causing the edge to
look like a large loop.
Is there a way to force "no splines"?
[View output image here.]
Thanks in advance for any help or suggestions!
strict graph G {
splines=false;
"html" [
shape = none
margin = 0
label = <<TABLE>
<TR>
<TD PORT="d">Isend(0)</TD>
</TR>
<TR>
<TD PORT="e">Irecv(1)</TD>
</TR>
</TABLE>>
];
html -- a;
html -- b;
html -- c;
a -- c;
html:d -- html:e;
}