the val don´t keep the SBUF value

I am testing a routine with serial interrupt and I notice that the value is not transferred from SBUF. I notice this in uVison debug. What's happen?

Please help me.

follow my parcial intr routine

if(RI)
{
   c = SBUF; //<-- here is my problems
   RI = 0;
   if (istart + ILEN != iend)
   {
      inbuf[iend++ & (ILEN-1)] = c;
    }
}