This program:

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

int main (void)
{
	int f, j;
	
	j = 0;
	while (1) {
		f = open ("/dev/null", O_RDONLY);
		if (f == -1) {
			fprintf (stderr,"open (%i): %s\n", j, strerror (errno));
			abort ();
		}
		close (f);
		j ++;
	}
	return 0;
}

fails on 2.6.14-rc4 kernel with this message:

$ ./a.out 
VFS: file-max limit 50044 reached
open (55499): Too many open files in system
Aborted
$ 

This problem was reproduced on i386 and amd64 with
kernels 2.6.14-rc1 .. 2.6.14-rc4-git4