Pulling my hair out.... PLEASE HELP!!

A co-worker is trying to edit a line of text on a drawing on our
server, from his computer.
The text for this drawing is formatted as "Standard" style, where the
font is romans.shx and the BigFont is one of OUR company's customized
shape files. The radio box stating "Use Big Font" IS checked. We're
both using AutoCAD 2007, on Windows XP systems.

Using _eattedit, he types in the following string:

[D[4"x 6"

The result looks like this:

PL1/4?x 6? (Our customized SHX file allows the PLATE and FRACTION
characters but the INCHES/QUOTES character is not recognized.)

FROM MY COMPUTER, I typed in the same string on the same drawing...
also using _eattedit:

[D[4"x 6"

.... and the result is what we want:

PL1/4"x 6"

So I compared what my co-worker entered to what I entered and I
noticed his quotes/inches (") looked italicized when I brought them up
in the text editor. But the Text Properties and Attributes appeared
the same. In fact, EVERYTHING in the Enhanced Attribute Editor looks
identical to mine, and as it SHOULD look. So I saw nothing that would
tell me what was different.

So then, I looked at the Properties of this co-worker's quotes/inches
(") character and believe I found the problem.
In the TEXT category, under "Contents".... his quotes/inches
character (") reads:

{\fTimes New Roman |b0|i0|c0|p18;"}

It's being AUTOMATICALLY formatted/overridden as a Times New Roman
font! Remember, the drawing text is formatted to use another font
(romans.shx).

He is doing nothing differently than I would. And I'm editing/testing
the SAME drawing he is.

WHY WOULD THIS AUTOMATIC FORMATTING be happening on his computer? And
how do I "FIX" it??
Is there a system variable or some other setting/parameter that would
control this??? I'm tempted to believe there is.... because he tells
me this was not happening this morning. He went to lunch and, when he
returned, this was happening. I'm inclined to believe he inadvertently
hit a combination of keys that re-set [something]. What that
"something" is, I don't know.

ANYONE, please?

THANKS, in advance...

~Julie~