Lpc2000

I am getting an Invalid Instruction Exception trying to get my IAP 
routines running.  When it branches to the IAP service routine at 
0x7FFFFFF0, it goes to the next instruc which is invalid.  

==>>	0x7FFFFFF0 F7FFB580    LDRNVB    R11,[PC,+R0,LSL #0xb]
	0x7FFFFFF4 BC80F949    DD 0xBC80F949 ; INVALID OPCODE
	0x7FFFFFF8 4718BC08    LDRMI     R11,[R8,-R8,LSL #0x18]
	0x7FFFFFFC FFFFFFFF    SWINV     0xffffff
	0x80000000 DEADDEAD    CDPLE     CP14,0xa,CR13,CR13,CR13,0x5
	0x80000004 DEADDEAD    CDPLE     CP14,0xa,CR13,CR13,CR13,0x5
	0x80000008 DEADDEAD    CDPLE     CP14,0xa,CR13,CR13,CR13,0x5

R00=0x40000EF8
R11=0x40000F30

Here is the code snip:

void attrib_RAM FlashData(void) {
   	typedef void (*IAP)(unsigned int [],unsigned int[]);
   	unsigned int command[5];
   	unsigned int result[2];
   	// setup
   	IAP iap_entry;
	Disable_INT();
   	iap_entry=(IAP) IAP_LOCATION;
   	// Prepare to erase
   	command[0]=50;
   	command[1]=14;
   	command[2]=14;
   	iap_entry(command, result);
   	if (result[0] != IAP_CMD_SUCCESS) goto error;
...

It's pretty standard.  I don't know why it is causing this crash.
I must be missing something simple.

I guess I don't know where the PC is suppose to go after 0x7FFFFFF0.  
Seems like it should go to the handler routine for cmd #50, but it 
just drops to the next instruc.

Any ideas?

Thanks, Chris.