I have a ASUS H67M-PRO, Intel Core i3 2100. I notice sometimes, it takes longer to POST/boot up. I am shown the BIOS messages (as usual) but it takes longer for the single beep (which I think indicates OK), and the boot to continue, what might be the problem?
I did reset BIOS settings to optimal but it does not help. It also only happens sometimes. Although it takes longer it still boots as usual.
If you are running at default settings, I would see if an external device is slowing down boot time. I had an external hard drive that would cause my Gigabyt 990FX UD3 to take forever. Unpluging it from the system fixed the problem.
The only other time I have had a similar issue was with overclocking RAM. Since you are at default settings the RAm speed shouldn'd be an issue, but maybe you have an issue with one of the sticks.
You could try memtest or even running with just one stick and then the other to see if that sheds some light on the problem.