Problems running maxima on sbcl



I tried to get maxima 5.12.0 running on the windows port of sbcl 1.0.6.  
The compilation goes throuh. But when I start maxima I get:

--------------------------
......
 #<MODULE: destructuring-let> #<MODULE: declarations> #<MODULE: sloop>
 #<MODULE: info> #<MODULE: package>)
* (cl-user::run)

Maxima 5.12.0 http://maxima.sourceforge.net
Using Lisp SBCL 1.0.6
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
This is a development version of Maxima. The function bug_report()
provides bug reporting information.
(%i1) 2+3;

Maxima encountered a Lisp error:

 The value 64 is not of type BIT.

Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.
-----------------------------

Any hints on this?



Yours,
Reinhard Oldenburg