Automatic turn on problem

Dear Sir
I have an Intel m/b D845EPI/D845GVSR . When I turn on the power switch , the system automatically turn on. Normally we turn on the power switch and then we push the power button on the CPU. but in this case , I dont get a chance to push the power button on the CPU before that cpu turn on. Why happens like this? Is this because of any wrong configuration in bios? please give me a solution.

Like wise, I have a Gigabyte m/b GA-8VM533. When the system turns on , it shows TIME AND DATE did not set. I went several times to bios and changed the time. but after restarting same problem shows. why? please help me

Thanking You
Shaji