I presume your station is a Davis Vue and not a FineOffset, and have selected that in your settings, is that correct?
I am confused with your; station not found, data running intermittent, restart PC and starts collecting again. Could you clarify.
Have you ticked Debug Log to see what it says?
Cumulus 1.9.4 latest build 1099 and MX both running for me on Windows 8.
Paul