clock advance with SuSE 9.0 AMD64 on a laptop

Hello again My laptop is an Asus L5D. On the HD, SuSE 9.0 (kernel 2.4.21) and SuSE 9.1 upgraded into 9.2 (kernel 2.6.8). With 9.0, the system clock is always not on time after use. I have to go to bios and put the clock on time. No problem with 9.2 : the system clock is stable. How to explain such a behavior ? Kind regards Pascal