After installing mobilejoomla, and jumi [for scripting within joomla], I noticed I kept getting these notices like:
Notice: Trying to get property of non-object in C:/wamp/www/xxxx/modules/com_mobilejoomla
I traced the problem to the php pages that comprise mobilejoomla and noticed that the scripts [especially the legacy.php scripts for each template], kept looking in the URLs for 'Itemid' values.

My Solution was simple: add 'Itemid=1&' to any links you make to Jumi application pages and all the notices disappear pronto!
I just wanted to share!