Lee, it maybe the way the cache works on the mobile phone, way around this would be to make a brand new A Record or CNAME either work, make it mobile.allcorsa.co.uk (example)I have no idea why this is. Maybe one of the more technical users may be able to shed light on it.
Also, for those who asked, I'm in the process of setting up Tapatalk for you.
then all mobile phone's would have never visited that address before, hence the lookup on DNS would be the correct IP
Maybe this would solve the issue , and others with slower ISP's it "should" fix this problem also
or even use something like www1.allcorsa.co.uk
If you need help Lee, drop me a PM:thumbs_up: