I have a couple of large epub files (I also have pdf versions) that are about 20mb in size. It took a while for the Kobo to initialize after I installed them, but not too long. I installed them to an SD card. Now when I try to open one to read it I've been waiting for about 10 minutes while seeing a quote that shows up when loading a book, and watching the little progress star circle round and round in the top right corner. I understand that it is a large book and is quite complex so it will take a long time to load, but this seems excessive. I was wondering if it would make a difference to have the epub on internal memory? If this doesn't make much difference I'm wondering if I should load up the pdf version instead, but I'd rather have the re-flowed version. It's now 15 minutes and it still isn't viewing the book. I think I'll have to re-set.