Why doesn’t my app work on wp8 (part 1 of n)

We recently switched over to a Lumia 920 for testing our apps, and have found that some of our apps just don’t work correctly.

For instance, our popular Skied Demon ski logging app exhibits problems on Windows 8 on a Lumia 920.

It turns out that the problem is caused by setting up BitmapCache as the CacheMode on some of the controls to improve performance.  The ironic thing is that this fails on Windows Phone 8 and not on Windows Phone 7.

This may also be caused by the increased screen resolution on this particular phone though I haven’t yet been able to verify that.  I suspect that what’s happening is that a bitmap is being constructed for the size of the zoomed area.  As that size grows, eventually the entire thing falls apart.

However, I would have expected WP8 to behave at least as well as WP7.

So, that’s one (of presumably many to follow pitfalls, as we know at least one more of our apps is currently not working, probably caused by a store issue)