Ever since I upgraded to Lubuntu 12.04 (from Lubuntu 11.10), the scroll wheel on my mouse has not worked in AbiWord for moving up and down in documents.
The scroll wheel does still work in other applications I've tried--for example, it works in Firefox, Chromium, LXTerminal, XChat, Pidgin, Gedit, Leafpad, and LibreOffice Writer.
How can I restore mouse wheel scrolling in AbiWord?
You are likely suffering from bug 991399 where we can read that the Abiword version 2.9.2 packed with 12.04 is a development version that should not have made it into the release.
Mouse scrolling is still possible when the mouse cursor is positioned on the scrollbar on the right side window. If that is not a workaround for you you may need to downgrade Abiword to the last stable version abiword-2.8.6.