Hi! Great Hint, saved me some bucks too!

I read this hint a couple of months ago and could not get it to work on my eMac 1.42/512Mb. I first tried the boot menu, and got nowhere. I then went into OF and imediately saw I had no "ud" alias. I don't exactly recall what version of Tiger I was running at the time, 10.4.6 or 10.4.7 maybe.
Now, just this week, I tried it again... with success.
I still had to go into OF and type "boot ud:##,\\:tbxi", but no problems... well so I though.
First I tried a clone of my Tiger Install DVD, no luck. I got the grey Apple and then the "no entry" (circle with a diagonal line across.). The I tried a clone of a fresh install onto a local partition. No luck. A Panther install CD clone. Nope. An x-support bootable clone. Nope.
In fact, my first sucess was with an e-drive made with techtool(??) and then with a Tiger system that I had a backup from another system. I do not see the connection or why these particular partitions/drives worked.
Any ideas?
I tried looking at the "blessed" info from the successfull boot volumes but they didn't show up any differences fron the rest. I even tried to bless the volumes I wanted to get working, but got nowhere.
In my case, I definitely believe that updating to 10.4.8 (or maybe a security update) put the "ud" in my OF. Has anybody else had this happen?
Also, I have on occasion delved in to the OF for various reasons, and somewhere I read that you could write your own "alias" into OF that could be mapped to a startup key (ie: "u" for usb, like "c" for CD). I'll see if I can track it down again.

I have Mac OS X 10.4.8 but I still don't have "ud" in my OF. However, I have a lot of "usb"s listed. Does anyone else have this problem?