Maps no longer appear after upgrade to 3.5.1

Hi there,

I thought I'd upgrade to the latest version but now find that no only has all of the formatting changed, but also the GPX maps no longer show up.

I suspect it may have something to do with a clash with another extension, but I've no idea how to work that out.

The URL to my tracks page is:
http://www.segwaycentral.net/gliding/glide-routes

Any help would be very much appreciated.

Thanks,
Paul.