Omnia won't connect to PC

[Guest smartpicture]

I connected my Omnia to my Windows Vista PC using WIndows Mobile Device sync centre, all worked fine and things transferred from Outlook to my phone. Today I tried to do it again and it just won't connect. It says Disconnected in the SYnc Center, no noise that it used to make on connection, what next?

[Guest Steve_T]

Try,

Settings>Connections>USB To PC > toggle checkbox Enable/Disable Advanced Network Functionality