This questions is a result of an earlier question about jumping to a VF page in a browser from SFDC1 (Link to full site in Salesforce1?). On the iPad, it is possible to go to any URL from SFDC1 by using the javascript window.open call. No matter what parameters you pass in, the subsequent window always opens as an InAppBrowser window, not in Safari. Now once you are inside InAppBrowser, and you create or edit a record which has a lookup, clicking on the lookup icon takes you, as expected, to the standard lookup search layout. However, clicking on any of the search results has no effect. It does not take you back to the page being edited with the selected value populated in the lookup field. It just stays on the lookup search layout. This seems to happen on any object, with any lookup field.
Thx, Hamayoun