I'm using FSX + Acc. and I'm having a similar problem myself.  Prior to installing SP 2.6 I had 2.4 and all my planes worked fine.  After uninstalling everything related to the 727 Captain and installing the latest version, all my planes have been rendered USELESS!  I'm now unable to click on any of the buttons or switches in the VC.  It's enough to make me want to pull my hair out when I think about all the liveries and various fixes for the 727's bugs I'll have to reinstall if this new version doesn't work.  I've opened a ticket with customer support and hopefully they can resolve the problem.