I've seen one or two reports of page turning going the wrong direction or getting erratic after while before... However I can't find the post in question. I also can't remember which firmware it was about.
It sounds like a firmware thing though, I can imagine that three hours of non-stop reading can eventually fill up some cache or something fails to refresh causing erratic page turning problems.... and also seeing your Touch and Glo are both on the same firmware I think it might be firmware related, so not (necessarily) device related. Having said that, I don't know if this is a known bug for Kobo or if it has been fixed in the newest firmware (2.4.0).