SolidWorks Premium 2012 (x64) SP 5 and now Premium 2013 (x64) SP 3.0

Windows 7 Enterprise SP 1

HP Z400 Workstation w/ 8 GB RAM and NVIDIA Quadro FX 4800 graphics card

Occasional problem - For no apparent reason, keyboard shortcuts stop working.  Requires restarting SolidWorks to restore them.

Examples include ctrl+Q (force regen) and ctrl+O (open file) merely beep.  No error messages.  This "feels" like a Windows resource issue, but I can't confirm.  The SolidWorks Resource Monitor never alerts.

Also, we are running Adept (a revision control database) from Synergis Software, which is integrated into SolidWorks as an add-in and generates an Adept task pane.  Recently upgraded Adept from 2011 to 2014, but the problem occurred with both versions.  I honestly can't remember if this occurred before using Adept.

Any suggestions would be welcomed.