Problem using OCIDescribeAny with Oracle 8.0.3 on NT

Hi,

I am using Oracle 8.0.3 on NT 4.0 SP3 with Visual C++ 5.0. Whenever I call OCIDescribeAny with a valid table name I get an access violation.
If I call this function with an incorrect name I get the appropriate error message.
I imagine that I am doing something wrong but I am not sure what.

Chris

 OCIDescribe* dschp = 0;

 ret = OCIHandleAlloc((dvoid*)_envhp,

(dvoid**)&dschp,
(ub4)OCI_HTYPE_DESCRIBE,

       0,
       0);

 CheckError(ret);

 char* s = "show";

 ret = OCIDescribeAny(_svchp,

         _errhp,
         (dvoid*)s,
         (ub4)strlen(s),
         OCI_OTYPE_NAME,
         OCI_DEFAULT,
         OCI_PTYPE_TABLE,
         dschp);