Trouble Connecting PC to PS3 and 360.

[MBrown]

Lately my PS3 and 360 have been having trouble connecting to my PC. Every once in a while it will work but then an hour later I can't stream anything and neither console can connect to my PC. My PS3 and 360 both see my computer but they can't actually connect to it. I have everything allowed under media streaming on my PC (Windows 7) but I still can't get everything working properly. But weirdly even when my 360 can't connect to my PC in the xbox live interface, it can stream if I open up Media Center on my 360. What is going on here?