What does it mean when a receiver battery buzzes when connected to a quick charger?

Background: I have two batteries for my new H9 Texan: a 600 mah Futaba (Sanyo) NiCd and an 1100 mah JR NiCd. If I connect the JR battery to a slow charger, there's no buzzing. But if I connect it to my fast charger, the battery emits an audible buzz. Mind you, I'm not even charging the battery; I simply connect it to the quick charger and the buzz begins. Neither the slow charger nor the fast charger causes the Futaba battery to buzz.

Is there something wrong with the JR battery? Should I discard it?