Ever since installing '09, I cannot load my Simulation add-in. An error comes up that says "C:\.....\cosworks.dll cannot be loaded. Either the Add-in or one of its components is missing"

The file in question exists in the location it says. The other Premium options like Motion and Routing add-in just fine. Simulation is the only problem. My IT has tried everything my VAR can think of short of re-installing SW. This same problem also comes up when I try it on my coworkers computer. We are using multiple network licenses, one of which is Premium, the others are Professional. When I load in Motion, my SW goes and grabs the Premium license off the network just fine. Adding Simulation at this point doesn't work either.

Anyone seen this? Any ideas?