wrong addres of label

look just at this code:

Code:

console_begin:
    inc byte [ds:0b8000h+79*2+23*160]
    jmp console_begin
console_data:
console_stack: times 128 db 0                             ;segment stosu
console_end:

t_begin:
    nop
    jmp t_begin
t_stack: times 128 db 0
t_end:

when i jumped to t_begin the program crashed,
so i pushed nop between console_end and t_begin and everything is ok
here are listings of code with nop and without nop:

Code:

                                                console_begin:
00000BC5: FE 05 FE 8E 0B 00                         inc byte [ds:0b8000h+79*2+23*160]
00000BCB: EB F8                                     jmp console_begin
                                                console_data:
00000BCD: 00 00 00 00 00 00 00 00 00 00 00 00   console_stack: times 128 db 0                             ;segment stosu
          00 00 00 00 00 00 00 00 00 00 00 00   console_end:
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   t_begin:
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00               
00000C4D: 90                                        nop
00000C4E: EB FD                                     jmp t_begin
00000C50: 00 00 00 00 00 00 00 00 00 00 00 00   t_stack: times 128 db 0
          00 00 00 00 00 00 00 00 00 00 00 00   t_end:
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   begin:
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00

and the 2nd:

Code:

                                                console_begin:
00000BC5: FE 05 FE 8E 0B 00                         inc byte [ds:0b8000h+79*2+23*160]
00000BCB: EB F8                                     jmp console_begin
                                                console_data:
00000BCD: 00 00 00 00 00 00 00 00 00 00 00 00   console_stack: times 128 db 0                             ;segment stosu
          00 00 00 00 00 00 00 00 00 00 00 00   console_end:
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00               
00000C4D: 90                                    nop
                                                t_begin:
00000C4E: 90                                        nop
00000C4F: EB FD                                     jmp t_begin
00000C51: 00 00 00 00 00 00 00 00 00 00 00 00   t_stack: times 128 db 0
          00 00 00 00 00 00 00 00 00 00 00 00   t_end:
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   begin:
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00 00 00 00 00   
          00 00 00 00 00 00 00 00

as You see in the 1st example t_begin is in a wrong place...