#3 Grid out of index error message

[Chris Shaffer]

This error occurs in many places. For example:

If you do not select a group within the "Groups at"
section of the page and then use the mouse scroll wheel
to go through the list of groups, if comes back with a
"Grid index out of range" error message. (Chris Bisson)

I also get "List out of bounds[%d]" when I click on lines
in the grid for ships in production. (Andy James)

Is it possible to implement scrolling with the mousewheel?
Although I'll admit that I hated mouse wheels at first, I've
somehow subconsciously come to depend on them. Each
time I try and use it on the main map, it barks at me with
a "Grid out of range" message (Matthew Messana)