Does it also happen in a brand new useer account with the same files?
I remoted into her computer, and I tried my account. It does the same
"DDE Server Window: InDesign.exe - Application Error
The instruction at 0x00917873 referenced memory at 0x083c6f18. The memory
could not be read.
Click on OK to terminate the program"
Not quite the same as a brand new user, but maybe a good enough test. I'd back up the customizations, uninstall, including removing prefs, reboot, run the CS5 clean tool (Resolve installation problems with CS5 Cleaner Tool), reboot, and reinstall. Usual caveats about non-essential programs running, especially virus and malware scanners, apply.
I gave this a try today, but it didn't work.
Is it all old files, or just some? If you make a new one and then reopen it, does it show the error on the second close?
I checked for a crash report, but there isn't any. The error doesn't even
show up in Event Viewer. I caused the error again to be sure. I did create
a new file with a couple text fields and 1 picture. I saved it, closed it,
reopened, and closed again. I could not create the error with that file. I
can, however, consistently do it with other files.
That sort of worked. When I ran the initial export of the file and closed
there was no error. If I opened the newly created idml file and closed it
would throw the same error. I decided to look into a theory I had about
saving. I loaded the original file that was giving me trouble. I made a
small change, saved the file, and closed. The error did not come. I opened
the file again and closed. The error was produced. It seems it happens
when you load an existing file and don't save/export your work.