New Post: Xamarin ios timespan axis freezes on iphone 4

I have created a timespan axis graph that is the same as the example in the oxyplot monotouch examples app.

When the app goes to load the graph is freezes when running on an iphone 4. I have tested this with an iphone 5 and it runs perfectly. There is no error reported in the application output in xamarin studio. The app just completely freezes.

This also happens with the oxyplot monotouch examples app when selecting the timespan axis graph.

Any ideas why this is happening?

Liam