Verified. Worked fine on my Macbook (i686-apple-darwin9-gcc-4.0.1 (GCC) 4.0.1 (Apple Inc. build 5493)), broke on a Linux box (gcc (GCC) 4.1.2 20070626 (Red Hat 4.1.2-14)).
This will drive me crazy.
Edit: it has to do with 32-bit and 64-bit. When I compile explicitly as 32 bit on Linux (which is a 64-bit machine), the error goes away. Probably related to how he casts everything to an object, and assumes things will be in certain places.
Both repl mode and file mode just spew errors.
gcc version 4.1.2
[briang@ ~]$ gcc lisp.c -o lisp
[briang@ ~]$ ./lisp test.lisp
> Error.
> Error.
> Error.
...