There is no difference in stability between XP and Vista (I run both on my 40% overclocked e6400 with absolute stability). The only difference is, as mentioned, crappy drivers in Vista, which should have been taken care of before your overclocking attempt either through Windows Update or else by downloading the latest from the Asus website.
If this is a serious request for help overclocking your processor higher, try following the steps in the sticky guide in this forum (including adjusting voltages, small increases in fsb, orthos testing for stability, etc). If that fails to help you exceed your apparent 2.4GHz limit (keep in mind that this already a 33% OC) then you should ask for help in finding something else to try.
You have solid components there that should allow you to hit 3GHz or higher with proper overclocking. However, keep in mind that no specific CPU is guaranteed to hit a particular speed when overclocked. If you absolutely must have more power you are always better off paying for the faster chip rather than hoping that a cheap one will OC well.
But obviously from people's responses, they are getting tired of your posts that seem to point to Intel sucking and AMD being better (or more "snappy" to quote your other posts).