Printf not working in PK51

I am using printf statement in my projerct using PK 51 compiler for the target P89C668. But i found some trouble in it.

My code is,

void main(void)
  {
     SCON = 0x50;
     TMOD = 0x20;
     TH1  = 0xFD;
     TL1 = 0x00;
     TR1 = 1;

     SBUF= ' ';
     puts("\n Hello World");
     TI = 0;

     SBUF=' ';
     printf("\n hai");
     TI = 0;

   while(1);
 }

The puts statement works with serial port but the printf statement is running infinitely i dont know the reason for it.

but this one works with the previous of uVision 2.

can anybody what is the problem in the program.