/stand/sysinstall freezed on FreeBSD 7.1 install

[Julian Bolivar]

Dear Friends,


I try to install FreeBSD 7.1 AMD64 beta 2 in an Intel Core 2 Duo and 
motherboard MSI 975X Platinum V.2m, but when /stand/sysinstall try to 
start from the installation CD, the system freezed and don't continue 
the install process.

Anyone know how to solved this problem to install it

Thanks and regards,

Julian Bolivar