PED appears to unmount drive on exit

[tetracorp]

AmiBlitz3910final.lha, Workbench 3, emulated on FS-UAE.

I run PED from the command-line like this:

cd AmiBlitz3.9
Amiblitz3 -PED

Upon quit, typing "dir" or another command operating on the directory brings up a "Please replace volume ___ in any drive" requestor, as if the disk has been removed or is not mounted. However, the drive is still actually mounted, and I can "cd" to it again, but until I do so, the OS insists the drive is not mounted.