The resetActivePageHeight is apparently fired after a iframe finish loading. This causes a major problem.
In my case, I have an iframe the top of the page and a long list with some search results.
It takes 1-2 seconds to load the iframe content, and in that time the visitor has most likely scrolled down the list. When the iframe finish the load, then the page will scroll to the top again, which is very annoying for the visitor.

The issue can be seen in this example:
http://www.w3schools.com/code/tryit.asp?filename=F0K7K1TQOJG3
In the example, I have included a js function to scroll down the page onpageshow which is comparable to a user scrolling down the page before the iframe has finished loading.

I have tried to use a offline version of jquery mobile. If I remove the content of the resetActivePageHeight-method then everything works as expected. However, this cannot be the right way to fix the problem because there must be a meaning with the resetActivePageHeight.