Player stopped working after site transfered to different server

I had the player working on a windows server, I've since transferred the site to a ubuntu linux server and can't get the player to work again.

Points worth noting:

I created a new key in services, added that key to the player config.xml. I also changed the site url (its now local before mmoving onto a live linux server).
All file directories are exactly the same as they were on the original server.
The player doesnt actually attempt to load, only a white background is displayed with 'loading 100%'. At the bottom of the screen is says 'transfering data from localhost...'.
Its now operating with php5.3

Is there anything obvious i've missed out? Any pointers on how to debug this?

thanks