Babel evaluation of Calc block not working, bug in Calc?

[dieter@duenenhof-wilhelm.de (H. Dieter Wilhelm)]

Hello Orgers,

please consider: Emacs -Q and evaluate the following

#+BEGIN_SRC emacs-lisp
(org-babel-do-load-languages
 'org-babel-load-languages
 '((calc . t)
   (emacs-lisp . t)
   ))
#+END_SRC

#+RESULTS:
| (calc . t) | (emacs-lisp . t) |

The following works as expected

#+BEGIN_SRC calc :var V=3
V + 4
#+END_SRC

But now we are getting: byte-code: Symbol's function definition is void:
v!

#+BEGIN_SRC calc :var v=3
v + 4
#+END_SRC

Calc thinks that the variable v contains a function even though nothing
should be undefined for v and when trying debug-on-entry for
calc-var-value the expression (boundp v) returns t!?  I'm stuck at this
point, could you please have a look, I've no idea how to debug this
further.

GNU Emacs 24.3.93.3 (x86_64-unknown-linux-gnu, GTK+ Version 2.24.24) of
2014-09-17 on vsl28t2g With the latest org-mode from git 

Thanks
        Dieter
-- 
Best wishes
H. Dieter Wilhelm
Darmstadt, Germany