_CLRBTS & _SETBTS not working in RPGLE (at least not for me!)

I am trying to use these functions to manipulate bits in a
single byte character string.

I have a similar function,  _TSTBTS (test bits) working
perfectly.  In fact, I have replaced all the testb opcodes
in my programs to use this function.

I can not get the _CLRBTS or _SETBTS to function at all.
The program compiles and executes normally, just no bits are
getting cleared or set. I suspect it is my prototype
definition as I have a hard time, sometimes, interpreting
the MI and C examples into RPG.  (though these seemed fairly
straight forward)

Has anyone before used these in a RPGLE program and perhaps
have a RPG prototype and call example to these functions
that you could share?

If anyone would like to see the simple test program in which
I am attempting this,  you can send an email to
craig_rutledge@mohawkind.com , I will reply with the code.

Thanks.
Craig Rutledge
http://www.alltel.net/~craigru/jcrcmd2.html
as400 freeware utilities and games