Logic Studio (Logic 8) and Synthogy Ivory 1.5

I'm a longtime user of Tiger on an older mac. I purchased a macbook pro recently which shipped with Leopard. I bought an older copy of Ivory awhile back (ver 1.5 apparently) and just spent 2 hours loading it on my laptop. (Yes...I loaded the AU version). I opened Logic and Ivory does not appear under the Software Instruments in the track setting.

I assume the new Logic is compatible with Ivory and I'm trying to figure out where 3rd party software instruments are stored. I'm curious if I need to move a file into a particular folder or something in order for Logic to find it. This is my first dealing with a 3rd party software instrument, but when I was dealing with samples here recently, in Tiger there was the "Logic" folder where all the factory stuff was stored, but then there was the "user" counterpart folder to this where 3rd party things were stored. (took awhile to figure this out...). I'm not used to Leopard yet, but I couldn't find this in leopard's finder window and I assume the same logic applies to software instrument outside Apple's factory stuff. I couldn't find any reference in any of the Logic literature either that tells you where things get stored so I thought I'd ask here to see if anybody can clue me into figuring out why Logic isn't seeing it.

Sorry bout the long winded explanation, but does this make sense to anybody??

thanks in advance...