Gcc4 Frame Pointer Issue

If anyone's interested we use the following function to dump the stack of a UCOS thread, should be fairly straght forward to modify for none UCOS systems:

// these variables generate by linker, using standard linker script.
extern char _start;
extern char __etext;  
extern char __ram_exceptions_start;
extern char __ram_exceptions_end;
void DumpStackTcb(OS_TCB* a_pTCB)
{
  void* sp = 0;
  //lint -e{522}
  __asm ("mov %0, sp" : "=r" (sp) );
  void*   pTextStart   = &_start;
  void*   pTextEnd     = &__etext;
  void*   pExceptStart = &__ram_exceptions_start;
  void*   pExceptEnd   = &__ram_exceptions_end;
  OS_STK* pStackBottom = a_pTCB->OSTCBStkBottom;
  OS_STK* pStackTop    = a_pTCB->OSTCBStkBottom + a_pTCB->OSTCBStkSize ;    // OSTCBStkSize is num of elements, not bytes
  OS_STK* pStackCur    = a_pTCB->OSTCBStkPtr;
  
  isr_printf("TS(0x%x) TE(0x%x) ES(0x%x) EE(0x%x)\n", (unsigned)pTextStart, (unsigned)pTextEnd, (unsigned)pExceptStart, (unsigned)pExceptEnd);
  isr_printf("id(0x%x) sb(0x%x) st(0x%x) ss(0x%x) sp(0x%x) sp(0x%x)\n"
    , a_pTCB->OSTCBPrio 
    , (unsigned)pStackBottom
    , (unsigned)pStackTop
    , a_pTCB->OSTCBStkSize * sizeof(OS_STK)
    , (unsigned)pStackCur
    , (unsigned)sp
  );
  
  u32 Cnt = 0;
  for(OS_STK* pStack = pStackCur; (pStack >= pStackBottom) && (pStack < pStackTop) ; pStack++) {
    void* pPossibleAddr = (void*)*pStack;
    if(((((unsigned)pPossibleAddr) & 0x3) == 0) &&
        (((pPossibleAddr > pTextStart) && (pPossibleAddr <= pTextEnd)) ||
        ((pPossibleAddr > pExceptStart) && (pPossibleAddr <= pExceptEnd)))) {
      u32 PrevInstr = *((OS_STK*)pPossibleAddr-1);                                                // check if instruction before poss. return address is a call
      if( ((PrevInstr & 0x3f) == 0) || ((PrevInstr & 0x07ffffff) == 0x003ee83a) ) {               // check call / callr
        isr_printf("0x%x: ra(0x%x) pi(0x%x)\n", Cnt, (unsigned)pPossibleAddr, PrevInstr);
        Cnt++;
      }
    }
  }
}