Why won't my archstyle.shx work on R2004 anymore??

I have been using AutoCAD 2004 for years, and using archstyle.shx as my main font. It has worked perfectly. I installed AutoCAD 2013 yesterday, and copied (not moved) the font into the 2013 font folder. I made sure it is still in the 2004 folder. Now, when I try to edit text that is archstyle in 2004, I get an error message saying "There is not enough memory to complete this operation. Try closing other applications to free more memory." It takes MANY times of hitting the X or the ESC button to close this message. Other text, using other fonts, edits fine. AND, in 2013, archstyle edits just fine. I have wayyyy enough memory on this new computer, and this is evidenced by the fact that archstyle edits in the newer version of CAD. I am not yet used to or comfortable with using the new release, and ALL of my work is in 2004, so I really need to be able to continue to edit my work in 2004. Thank you for any help you can provide!

My guess is you have a 64-bit version of AutoCAD 2013. Is that correct?

Yes. So I might see why the font might not work with the NEW AutoCAD, but why does it now work with the NEW and not with the OLD? It worked with the old yesterday.

Could be a pathing problem.

Is AutoCAD 2004 installed under the Program Files (x86) folder?

I was very careful to COPY the file, not MOVE it. I went back after the trouble started, and there it is, in both font subdirectories.

Is it in this folder...?

C:\Program Files (x86)\AutoCAD 2004\fonts

yep...now, I DO notice - in both the 2004 and 2013 font folders - that the little icon next to the font name is red, versus the other SHX fonts which are not only black, but have a little SHX in them.