So, had you not used it in the 10 months since the update was released? When the updates are released, the change log is posted here, on Get Satisfaction, and often on the Kobo blog. You may wish to google for it.
I took 30 seconds and found several posts and threads about 1.9. Here is one of them:
https://www.mobileread.com/forums/sho...80&postcount=3