[Dev-C++] Free memory problem

Hi, all,

I met a problem when I free an array of points. The source code is as
following:

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

char *http_parampos[255] = { "name=rule1",
                             "protocol=tcp",
                             "sourip=172.16.12.53",
                             "sourport=3256",
                             "desip=172.16.12.98",
                             "desport=9685",
                           };

int main(void)
{
   int a = 5;
   int i = 0;
   char *value[7];
   char param_name[40];
   char *param_value;
   int index = 5;

   for (;a >= 0;a--)
   {
      strncpy(param_name, http_parampos[index - a], sizeof(param_name));
       param_value = strchr(param_name,'=');
       if (param_value)
       {
          *param_value = '\0';
          param_value++;

          value[i] = malloc(sizeof(param_value)+1);
          strcpy(value[i], param_value);
          printf("value[%d] = %s\n", i, value[i]);
          //free(value[i]);
       }
       i++;
   }

   value[6] = 0;
   i = 0;

   printf("come to error!\n");

   for(i = 0; i < 6; i++)
   {
         free(value[i]);
   }

    getch();
    return 0;
}

When I tried to free the memory, it breaks down. I have tried these code
with gcc and it works. And if I free the memory just after I malloc the
memory(see the coments line), it also works.Could anyone tell me what was
wrong with my codes?
Thanks in advance.

BR,
Daniel