[truejules]

SOLVED (in a way) After much hair pulling I narrowed down the problem to the Propellerhead driver for rewire. I had updated my Waves and I believe it installed a new rewire driver that my old version of Sibelius couldn't work with. I tried to test this theory on an old machine but I couldn't find the right driver for Sibelius (1.8.2) as a stand alone download, just an old version. Could this be because Propellerhead has moved on and doesn't support this old stuff? Uninstalling Sibelius and reinstalling didn't fix it on either machine. So, I bit the bullet, upgraded my Sibelius and violá ProTools recognized it on both machines.

I am not an expert on any of this so my theories may be wrong, but the ultimate fix was spending money and moving on. I'm posting this for anyone who might run into the same thing, at least they can read through my process which may be helpful.