I can`t run user program with Bootloader in PIC18F4520

[Enrique P. (flote21)]

Hello,
I am fighting against the bootloader in a PIC18F4520. I loaded this 
bootloader:

http://www.sectiongo.com/main/pic18-...xample-in-xc8/

And the user program is written in the memory, but I am not able to run 
the program. I dont know what can be the problem but when I read the 
memory of the PIC, I appreciated differences in the the first positions 
of the rom memory between the same program loaded with the bootloader 
and the same program loaded with the microchip programmer..

Anyones had the same problem?

Thanks.