Replying to My iTunes stops playing music

new problem in my itunes

i can't poke around the itunes store looking for new stuff while listening to my itunes stuff that i already have. i can play songs from my itunes but when i hit the store, the music stops.

anyone have a solution?
thanks

oh and another problem
i can't play audio/video on adobe premiere pro unless i'm actually looking at the program. like i can't put firefox in front of adobe, or else everything in adobe will stop too.