problems with 64 bits fedora

[Stefan Stefanov]

Hi,
I got computer with 3500+ Athlon 64 CPU. First I
installed FC3 for 32 bit succesfuly and then I decided
to install the proper one for this computer - FC4 for
64 bits.
I am very surprized by the fact that while the 32bit
FC3 installs, the 64bit FC4 as well as 64bit FC3 do
not install!!!
What happens: I boot from CD1 and it is OK up to the
moment when the software packages are to be installed.
It freezes (usually during kernel installation) and
nothing can be done.
I thought of a hardware problem and replaced the
CD-driver and the harddisk. Same result.
>From the BIOS: 
IDE Primary Master _NEC DVD_RW ND-35
IDE Third Master HDS722516VLSA80 (this is 160GB ATA150
harddisk)

Please help!

Best regards,
Stefan