Problem Breakpoint

Hi! I have a problem with GDB and i don't know if is a bug or maybe i made a mistake

I'm using the last GDB 7.6 on Linux Mint Debian and i'm tryng some easy example of cpuid from the book:

Professional Assembly Language of Richard Blum.

The problem is that when i put a breakpoint after the nop instruction, for example

break *_start+1

and then i run the program, i have this error:

Warning:

Cannot insert breakpoint 1.

Error accessing memory address : Input/output error.

If i run without breakpoints the program ends end exit without problems so...i think there isnt any error

in the code that i copyied and pasted from the book.

Thanks a lot for your help and greetings from italy.