After upgrade, a few workstations were getting the error after downloading any Juniper applet: "The application has failed to start because the application configuration is incorrect" Windows error. The event log shows an error in a service called SidebySide.
I've resolved this problem, and just wanted to inform the masses.
Turns out there is a bug in the Microsoft Virtual C++ that makes the C runtime fail. (VC80.crt) The Microsoft VC++ 2006 SP1 fixes this. I haven't test the VC++ 2008 SP1 yet, but I would expect this will fix the issue as well.