I'd like to point out that you need to purge libzlibrary, not just fbreader to fix this issue. That fact is not initially clear (to a linux neophyte such as myself) to someone reading this thread.

After reading this thread, I tried to just purge fbreader and then reinstall. No luck.
So I again purged fbreader, then libzlibrary, then reinstalled fbreader 0.10.7-5 via the app mgr. (btw, I assume the H in HAM stands for Hildon?)
And now the volume keys can scroll. I do alot of reading on my phones, so a good ebook reader is a killer app as far as I'm concerned.