iPhone 4 no longer plays thru a charging speaker base...

Since I've upgraded to the newest software 4.2.1 I found my iPhone 4 will no longer play in my speaker bases. I have a JBL OnStage mini and a Sony clock radio base. The odd thing is that both bases will charge the iPhone, I'm just not able to play music thru them. I'm not exactly sure when this started to happen, a few weeks maybe, but I'm wondering if it's a software issues, or an issue with my iPhone where it plugs into the base...any ideas/suggestions??

Thanks