my table don't work

Hi, i have a trouble with some tables in Guide. I create 3 tables of 10x2 in Guide, fisrt column is editable and the second no. In the first column, the object is introduce positive numbers that represent axiss positions. in the second column, the code have to fill it with the difference between each axiss position to trigger this i create a button 'guardar' and a button 'limpiar' to clean the table. I don't understand the error. My code is:

GBX is button's tag ('guardar'), EPX is the follow table:

Matlab show me these errors, when i push button 'guardar' values change:

when i fill until row 10 and push 'guardar':

Finally when push button 'limpiar' my table only let me fill the row 1. HELP PLEASE :(