Problem with ng symbol in exercises

Hi,

I recently started with the Korean course (Korean-German to be exact) and I want to report a bug:
I’ve installed the korean keyboard in Windows (7) and it seems to work except for the ng symbol (the circle). Memrise does recognize it when the ng is used in a syllable with other letter, but not alone. So I had to copy the ng symbol from an answer and paste it in each subsequent exercise asking for “ng”.

Best regards,
Gunnar

Update: Same issue with the letters d,r.