I was testing some changes I've made in the 1.7 data code against mobile and in review of the jqmData functions I found that you were calling $.hasData( elem, key ) - $.hasData only takes one argument - it just tells you if there is even a data cache for the object.
$.hasData( elem, key )
This makes me wonder if jqmHasData is even a necessary function - if it is, I could see it as a function that checks $.hasData then loops $(elem).data() for any jqm namespaced .data() keys perhaps.
After conversation in IRC today - I'm leaning towards the fact that you don't even need this function in your API...
Fix for issue #2455
I removed .jqmHasData(). we will re-add it when .jqmData() has the right behavior which is to return a hash with only the data in jQM's namespace