Install over FC SAN works, boot doesn't

[isplist at logicore.net]

I am able to install Linux over the FC network and onto a storage volume. 
However, when I try to boot these installs, I only get a blank screen and 
cannot boot.

I have found that I can install the /boot directory to a flash card on each 
blade and then am able to boot fine with swap and root on the remote volume. 

Why is this and how can I make my install 100% remote?

Also strange (to me at least), I have found that if I connect the multiple 
volume storage device to the rest of the FC network, already installed 
machines with Qlogic cards in them no longer boot. They come up with many 
errors and all finally stall at the syslog starting point. Disconnecting the 
new storage allows them to boot again.

I believe this has something to do with LUN masking/zoning (which I've yet to 
learn, have to start reading Brocade 2800 docs next) but what I don't get is 
why the new blades can see their own LUNS if installed as noted above with 
flash /boot, but old machines get stuck?

Rather confusing.

Mike