Thanks again AndyC for your help.
Edited post as although the command was invoked on the page load, somehow i lost any reference to mcstore, which is required by our app.
So finally i now have this working, one of the key items was the InvokePolicy which had to be set to
AsynchronousLowPri, set to any other and it wouldn't work.
I also found having "Model" navigate to the page and setting the FirstRun value to true, overcome
any issues with the code.
Thanks
If anyone needs an example, if having similar issues just ask and i'll post the code.