Cubase 6 - lost sound output

I am running Cubase 6 x64 bit on Win7x64. For a while now I have been getting no sound output when I first boot Cubase however when I’d close it and reopen it the sound came back. Today it is finally gone for good. I typically use jackrouter as my audio device however I also tried using the native asio::echo pci driver (I use a Layla 3G sound card). I have no problems with jack or my echo drivers in any other applications - only Cubase. I didn’t see anything in a log file (assuming I looked in the right place). I would love if someone could point my in the right direction to troubleshooting what might be going wrong here. Thanks in advance.