load and autoload fails when ibase # 10



I observed

volker at uvw32:~$ rmaxima -q
(%i1) obase:16$
(%i2) ascii(122);
(%o2)                                  z
(%i3) quit();
volker at uvw32:~$ rmaxima -q
(%i1) ibase:16$
(%i2) ascii(7a);
loadfile: failed to load
/usr/local/share/maxima/5.29.1/share/stringproc/stringproc.lisp
 -- an error. To debug this try: debugmode(true);

Can someone please explain this mechanism? The path-string is
displayed correctly but the file can't be (auto)loaded.

Volker van Nek