Update bios of the mobo is always a good idea for supporting the last cpus.
The last bios for your mobo is the 1007c:
P4S333 (without LAN) BIOS 1007C
Support CPU Frequency multiple to 28x and micro-code update. It can support P4-2.5/2.6GHz.
Fix Win98SE not be installed if IDE Ultra DMA Mode.
Fix CPU Information not showed under WinXP
It seems that SIS chipset doesn't support all the "northwood" cpus, only the INTEL PENTIUM 4 2,6Ghz max.
Anyway, your bios (1007) supports the same cpus, so it wouldn't necesary any update of your bios:
P4S333 (with LAN) BIOS 1007
Support CPU Frequency multiple to 28x and micro-code update.It can support P4-2.5/2.6GHz.
Fix Win98SE not be installed if IDE Ultra DMA Mode.
Fix CPU Information not showed...