Not getting Text Msg alert sounds while listening to music

[sprint_user101]

I am listening to music on my PPC 6700 with TCPMP and a stereo headset adapter.

Anytime that I get a text message, I hear nothing over my headphones. The only thing that I get is a pop-up notification on the screen (but no audio alert over headphones). This does me no good because when I'm at the gym, I have the 6700 in my pocket where I can't see it. I went to settings and made sure that all the alerts and sounds were turned on for text messages, but still nothing. I noticed that when a call comes in and I'm listening to music, I hear the ringer over the headphones, but not with text messages... doesn't make sense?

I rely on these text messages for my company and require immediate notification. Can anyone help?