Two ways of displaying a primary key in ER database diagram?

[Docs@discussions.microsoft.com API Docs]

I am working on a large database diagram (150+ tables), in Visio Professional
2003, SP-1, on Windows XP.

The formatting of primary keys appears to happen one of two ways, randomly,
as far as I can tell. I do have it set to put the primary key at the top,
with a divider line - that works fine, and the text is in boldface, which is
fine. But sometimes the field name is underlined, with "PK" in the left
column, and sometimes the field name in not underlined, and there is no "PK"
in the left column.

I can find no pattern - it's about 50/50 each way. And I haven't found how
to force them to format all one way or the other, which would be nice,
because the whole point of this exercise is to print a professional-looking
diagram (that is, not just for internal development use).

Has anyone run across this? Do you know how to fix it? Do the differences
in the formatting mean something?

Thanks for any input!

[API Docs]

Something else I've noticed - maybe this will turn on a light bulb over
someone's head: The tables where the primary key is labeled with a PK, and
is underlined, also say "<fieldname1> identifies <thistable>", then, for all
the others, "<fieldname2> is of <thistable>", "<fieldname3> is of
<thistable>", etc.

I'd like all the tables to work this way. Any ideas, anyone?

Thanks.

[API Docs]

A partial "Aha!" here, but it still hasn't led me to a solution - the tables
that were reverse engineered from a database are displaying one way (no "PK",
no underline on the field name), while the ones I added "by hand" *do* show
the "PK", and the field name is underlined.

I initially didn't think there was a pattern there, but there is actually a
direct correlation.

I've got the problem cornered and trembling... Now what?

[API Docs]

OK, I finally learned how to contact tech support, and got a very helpful guy
who figured out the answer to this one.

If you have a table with primary key specified, but it is only showing in
bold (not underlined), and "PK" is not displaying next to it, here's how to
fix that:

Select the table.
In the Database Properties window, under Categories, click Primary ID.
Under "Generate Key" (bottom left), it probably says "No Key".
Pull that down, and select "Primary Key".

<Finally...>