Flushing The Keyboard Buffer

I've run into a problem and I cannot resolve. I am designing an Excel Application in VBA. During the execution of the VBA code, the user will press different keys on the keyboard. These keystrokes are determined by using the GetAsyncKeyState Function. The problem happens when I exit from the VBA code and move back to a worksheet outside the code execution.

Lets say a user has pressed the 'Q' and 'X' key just prior to the final VBA subroutine running and releasing the worksheets back to the user. On the worksheet, in the selected cell will appear the 'Q' and 'X'. For some reason these keystrokes are not 'flushed' from the keyboard buffer prior to the code completion and are being transfered to the active worksheet. This is really annoying if I am testing the code in the VBA editor, because the spurious keystrokes will be placed in my VBA code, causing me to search for the out of place characters.