f18 i386 installer memory requirements

Wed Jan 9 00:47:53 UTC 2013

i'm trying install f18 on older i686 machine (1.8GHz P4 CPU/512 MB
RAM/160 GB HDD/Radeon 9000 64MB graphics), doing NFS graphical
installation with XFCE desktop (and several add-ons groups).
Installation started from installation CD (images/boot.iso image),
anaconda 18.37.8. Install CD Media check is fine.
Machine always stop respond in "Checking software dependencies..."
phase; CD-ROM permanently rotate and it's all.

I suspect this may be caused by insufficient RAM (althought I was
hoping that 512 MB will be sufficient - F17 requires 768MB and it's
installer seems be much cleverer and more functional than this in
F18).
Release notes and Installation guides F18 drafts seems not contain
info about HW requirements, can someone say it?

TIA, Franta