Sparkweb + SIP

I’m having problems getting sparkweb to make SIP calls. I have configured the openfire SIP plugin and am able to make calls via the Spark client.

However, when I attemp to use sparkweb, I get the error that my phone is not registered. Prior to attempting to use sparkweb my status in openfire was ‘Registered’, but as soon as I attempt to make a call in sparkweb it changes to ‘Unregistered’.

Any ideas as to why this would happen?