Azure VM Status Running (Provisioning timed out)

I've created a Windows 2008R2 Azure VM from a vhd file. I ran sysprep on the vhd before uploading it.

The server was setup and provisioned in a matter of minutes, I could connect to to it and login and all looked good.

I then wanted to change the local IP address from 10.2.0.4 to 10.2.0.21.

I first checked that the 10.2.0.21 IP address was free which it was.I then ran,

Get-AzureVM -Servicename mywebservicename -Namemyvmservername | Set-AzureStaticVNetIP -IPAddress 10.2.0.21 | Update-AzureVM

This was acknowledged as successful.

The server then restarted but when it came back on the status seemed to stay asRunning(Provisioning) for a long time. 

2 and a half hours later it has just changed it's Running status to Running (Provisioning timed out).

Why did it take so long to start up and why has the status reported as provisioning timed out. How do I get the server up and running again?

Thanks