My remote update routine.

// --- Local(static) Variables ---
typedef struct
{
unsigned char ucData[PAGE_SIZE]; //128
} tPageSize;

typedef struct
{
tPageSize Page[MAX_PAGES]; //32
} tPageFormat;

tPageFormat code tNewFirmware _at_ LOCATION_NEWFIRMWARE; //0x3800
tPageSize xdata tFirmwareData;

unsigned int xdata g_uiPageAddress;

static unsigned char xdata g_ucDataCount;
static unsigned char xdata g_ucPageCount;
static unsigned char xdata g_ucPageTotal;
static unsigned char xdata g_ucCheckSum;

unsigned char UPG_ProcessEvent(unsigned char ucData, unsigned char ucState)
{
unsigned int uiTemp; // To remove the dependency on library

Switch (ucState)
{
case 0: // Init Remote update
... ... ...
break;

case 1: // Receive data
... ... ...
// if last page, return TRUE
break;

case 2: // Start updating
... ... ...
// Use Watchdog for Software Reset
WDTRST = 0x1E; WDTRST = 0xE1;
while (1);
break;
}
return FALSE;
}

Any ideas why my hex code at 0x3800 is so dependent on other modules variables?

Thanks.