Dallas RTC 1305 and interrupts

Hello All, I started a project which uses a PIC16F876 and a RTC DS1305 from Dallas. There is no problem to read and write the registers. My only problem is the interruption . I connected the INT0 for the RTC to the RB0 pin of the PIC (I used a 5k pull-up resitor). I configured correctly (I think ) the registers to activate a interrupt every second . When I test my program, it appears that the INT0 goes low once. No matter what I try, the signal does not go high again in order to give the next interruption. By the way , the datasheet is not very clear (to me) what I have to do to let the signal go high. Your help is welcome. Thanks for reading, Georges.