The last 3 epub books I downloaded from the library keep freezing on my Kobo touch. I tried a reset but it didn't help. I can only go a few pages before it freezes again. The first time I had to do the reset, since then I have to hold the power button til it restarts but then it doesn't go back to the page I was on. I tried downloading a book I had read previously with no problems and it froze also. The WPLC library is out of suggestions.
Certainly sounds like a Kobo problem rather than an Adobe ADE one.
Have you tried on their forum as well?
One other thing that might help is to look at the contents of the Kobo from your file manager (Windows Explorer, Mac Finder)
Delete any files/directories on the Kobo called DigitalEditions, or .adobedigitaleditions, or similar.
You may have to set the file manager to view hidden files and folders.
I am afraid it probably won't help, I think the factory reset was more extreme than that.
Also check the Kobo site to see if there is a firmware update available.