skipping lines when compiling

I having problems with the C51 v6.2 not compiling certain lines of codes. I tried doing a search on previous posts but didn't see anything related.
here are the C statements:

if (msg_inbuf!=0)  // check if message waiting */
{               
	ack_flag=1;		// next received character should be ack*/
	Write_S();		// Send to tx buffer */
}

And here is the output:

; 			if (msg_inbuf!=0)  // check if message waiting */
			; SOURCE LINE # 1562
	MOV  	DPTR,#msg_inbuf
	MOVX 	A,@DPTR
	JNZ  	?C0363
	INC  	DPTR
	MOVX 	A,@DPTR
?C0363:
	JZ   	?C0242
; 			{               
			; SOURCE LINE # 1563
; 				ack_flag=1;		// next received character should be ack*/
			; SOURCE LINE # 1564
; 				Write_S();		// Send to tx buffer */
			; SOURCE LINE # 1565
; 			}
			; SOURCE LINE # 1566

I can't see any problems with the syntax. This is not the only section where this is happening. It seems to be treating the lines as comments. I can't figure out what I'm doing wrong.