All of a sudden, I am experiencing screen freezes and a host of "External Exception" Errors. This happens on any of three computers I have been using with my Flex 5000A running under Windows 7. The screen will freeze and I get the error messages. I have been using these computers for two years without any problem. I have uninstalled and reinstalled Power SDR (final version) without any success. If I power down the 5K, turn it back on, and reboot the software it will clear up the problem for a short time, but sooner or later I get the frozen screen. Could my 5K have a hardware problem?