I have seen this on numerous window 8 laptops and tablets with the keyboard.
I have also seen this with the onscreen keyboard with windows 7 and other programs as well.
It has to do with hold the keyboard functionality was programmed. and the changes in windows 7 and newer. Also you will note that the macro key swill not work in windows 8 or newer. This is the same issue.
Currently there is no fix, only the work around you have already found.