Dates problem

Hi! I have a problem with dates. I have a function that sum a duration in laboral days to an initial date. The problem come when the function reaches the last sunday of October, the data remains in the last sunday of October and make an infinite loop. The functions works fine i have test in all the cases and only fails in the last sunday of October. Can anyone help me? Thanks in advance. PD: Jochem home english is bad english :P -- Mario de Frutos Dieguez División de Ingeniería del Software y Comunicaciones CARTIF -Parque Tecnológico Boecillo