I've had the same issue for quite some time. I've got a PC running XP, with 130 gig of music being shared. Until I got my 770, it was shared primarily through my XBOX (not 360) which is connected to my TV (music, movies, etc play through the it). I've got a gym in the garage with an amp and some speakers. I used to use my MacBook Pro to share the music wirelessly but room in the gym is cramped enough. Enter the 770.

Media Streamer ALWAYS shuts down during an hours training - without fail - at least once. Either the app beeps and shuts down - it carries on playing the current song to the end despite not being displayed as a running app. I then just restart MS and carry on (waiting for another crash). Sometimes it will hang and nothing in Media Streamer works (minimise, file menu, etc don't respond). Usually you can get back to the home screen and even start other apps but MS won't quit. Once I managed to get it to quit by putting the screen cover back on - after a minute it beeped and asked if I wanted to shut MS down. However, I usually just power it off and start again.

My wireless connection is solid, I've not modded or installed anything too freaky on the 770, I'm technical on PCs and Macs but not linux so I'm waiting until I'm a bit further along the learning curve.

All in all, I'm stumped.....