iphone wont show up in itunes

[helloIphone]

When I first connect the iPhone in the cradle it iTunes will automatically detect it and sync perfectly fine
however when i disconnect it and later reconnect it, iTunes will not detect my iPhone
i have to restart my computer each time for iTunes to detect it
does anyone know why this is?

[glenrich78]

Mine did this one time a couple of days ago, but after resetting my computer and opening it up again it's worked fine...didn't need to change anything