If your program actually begins as you have shown I'm surprised it works at all. After your ORG 0h statement should be an SJMP or LJMP to the beginning of your actual code. As your program stands your MCU is trying to execute your message statements as code. And as the previous responses to your post have indicated, in the MCS-51 world it is always good practice to avoid the interrupt vector area (03h to 2fh) and begin coding at 30h. I would also strongly advise to place a RETI at each of the unused interrupt vectors to prevent unintended interrupts from vectoring your program into an endless stream of NOP's or other weird places in your code.

Good luck,

Hal