home sharing doesnt work on one of my computers, i am using the same itunes account for both computers. please help

ill call them computer (a) and computer (b).
on computer (a) whenever i try to open computer (b)'s library in home sharing it loads for a bit then itunes just jumps back to computer (a)'s music library.

BUT on computer (b) i can open the library for computer (a)

i am using the same itunes account for both computers,

am i doing something wrong?