I remember having that problem with Aldiko and the Archos 5IT I very briefly owned. I thought perhaps it was the tablet's horrible hybrid interface, but maybe it was Aldiko instead. Of course I'm not a fan of Android anyway as it seems to be a very immature OS and still caters to mobilephones. I get tired of having to jump through hoops to get apps to work. Too much hassle and way too many headaches.