I have this same issue. It's not my keyboard, it's SAGE. I can switch to Excel and type numbers just fine using the keyboard or the numeric keypad. It stops working in SAGE until I reboot the program. Did you ever get a resolution from SAGE Customer Service? 

Hello;

No resolution from Sage. I have talked to someone but, since it was working when i tried over the phone, no resolution was found. MY resolution is this one: once i type  something followed by '' :'' it will automatically put me off numeric pad and, i will have to press on ''shift'' to bring my keypad to work or, type in Excel doc will also do it. It is REALLY anoying but, i think nobody understood what my problem was. Still drives me crazy... if you find something, please post it here!

There is a resolution!  It has to do with the power management in the computer.  I spoke with Mauro A.  He had me go into the control panel, device manager, network adapter and realtec.  I then unchecked "allow the computer to turn off this device".    THIS has worked for me.  I hope it is okay that I posted his email but he was patient and knowledgeable.

There is a resolution!  It has to do with the power management in the computer.  I spoke with Mauro A.  He had me go into the control panel, device manager, network adapter and realtec.  I then unchecked "allow the computer to turn off this device".    THIS has worked for me.  I hope it is okay that I posted his email but he was patient and knowledgeable.