After a couple hours of head-scratching and hair pulling I've discovered what seems to be a very bizarre problem. My setup - MacPro running latest versions of Logic, OSX and VE Pro and VI Pro. I just recently purchased Dimension Strings so I upgraded to VI Pro. This is where the problem started though it took me a while to figure out. All of the sudden I was not able to connect to any instances on my VE Pro Server (locally and on my slave). I was trying this in a project I was working on, but when I started a new project I could open up the server interface in Logic and connect to everything as usual no problems...
So I opened up my in-prorgress project trying to do the same thing... but again no instances appeared. This in-progress project had 4 instances of VI Pro AUs open. Once I unloaded all of those TADA! the instances were all available in the VE Pro server interface. And as soon as I load up a VI Pro AU in Logic again the instances in the VE Pro server interface disappear and I am unable to connect to them.
This seems totally bizarre to me. I very very rarely have any trouble with VSL stuff and they sound great so this is very strange to me. Has anybody else experienced this? I guess it's not a massively huge deal since I can just put my VI Pro stuff in VE Pro and connect to it there... but still... seems really strange...