Key 'q' in the metaplaylist buffer

Hi emms-user,

again a small problem. In the buffer metaplaylist I would expect 'q' to 
kill the buffer (and C-h k also tells me this is the default behaviour). 
Unfortunately, if I press 'q' I get

kill-this-buffer must be bound to an event with parameters

Any idea why this is happening?

Many thanks in advance.

Best,