Start problem after the installation of OpenBSD 4.6

[aleunix]

While on my old computer since OpenBSD 4.3 i haven't problem, on the other computer more recent (dual-core) even now with the last release 4.6 after the installation i can't start the system.
Yes I have read the:
2 - Getting to know OpenBSD
2.4 - Reporting Bugs
but the problem is that i can write anything on the console, the system is totally freeze.
In summary it stop before finish to run the system.

If it's possible i would like install openbsd while in the worst scenario i think perhaps i will install freebsd or eventually netbsd.
I have a separate small hdd so i could avoid any eventual problem during the installation.

Note:
In the more old pc (single core) i use the 32 bit version while on the more "recent" pc (dual core) i would like use the 64 bit version.

Out:
On the pc where openbsd function (in this moment i'm on openbsd) i have tried to see a multi-card reader pen usb and it's works without problem.
I know it has nothing to do with the question but I wanted to share my joy.