nice() seems to have stopped working?

Since moving to this distribution, I notice that some of my programs that use nice() give errors when attempting to raise their priorities. In order to try and nail this down I wrote the following trivial program:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int main(int ac, char *av[])
{
int n printf("Trying nice(%d)\n", n);
if (nice(n) < 0) { /* Attempt to change priority */

     perror("Nice failed to change priority");
   }
   else {
     printf("Success\n");

}
return 0;
}

Running this program as root provides the following output:

/ # whoami
root
/ # niceTest 0
Trying nice(0)
Success
/ # niceTest 1
Trying nice(1)
Success
/ # niceTest -1
Trying nice(-1)
Nice failed to change priority: Success
/ #

Has anyone else experience this behavior?

Best regards,

Dave.
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hm?

See man 2 nice
[snip]
NOTES
SUSv2 and POSIX.1-2001 specify that nice() should return the new nice value. However, the Linux syscall and the nice() library function pro- vided in older versions of (g)libc (earlier than glibc 2.2.4) return 0 on success. The new nice value can be found using getpriority(2).

Since glibc 2.2.4, nice() is implemented as a library function that calls getpriority(2) to obtain the new nice value to be returned to the
caller. With this implementation, a successful call can legitimately
return -1. To reliably detect an error, set errno to 0 before the call, and check its value when nice() returns -1.

PS: See uClibc/libc/sysdeps/linux/common/nice.c for the gory details. HTH,