When I bought my Touch (N905B) it was freezing at every 15th or 20th pages for about a minute. Then it recognized my touches, and worked fine - for other twenty pages. It was really annoying

, and I don't know why it did. I have read that others are facing the same problem. My device had the latest firmware 3.11, updated via WiFi.
Factory reset, update, recopying epub book, not helped. I thought it is a hardware problem, or just the sw is soooo untested.

I have read somewhere, that freezes gone with 2.4 firmware, so I tried it.
If you don't how to install other version firmware, here's how I did it (you can skip this if you are familiar with manual upgrades): I downloaded, factory reset the book, then connected to my mac. The official Kobo desktop sw copied the latest 3.11 again, but before unplug I overwrote it with 2.4 (copy firmware onto the .kobo hidden folder) then disconnected the device. It recognized that there's something to install, so installed the 2.4 firmware.
So, with 2.4, FREEZES WERE GONE, WAS REALLY FINE. I have read about an hour without probs. Okay, but the software had less feature, and I have installed an ad supported version, so when I locked my device, it showed me ads, not my nice books. Mhhh..
I said I give it a try with 3.11 - but now, I was using a separatedly downloaded version, and as the same why I manually upgraded firmware, I upgraded to 3.11.0 (4d8eac1207, 10/16/14 to be exact). I did this 3 days ago, I have read almost 2 entire book (same book as before, same exact epub file) and it's working properly!
I use the same features, same books, and now its good. So, don't be angry, it will work, just try to upgrade to this version manually. The version what Kobo desktop installed onto my book, was not working properly as I mentioned before - sounds bad, but it is true.
I'm really looking forward to see a new update.