Segmentation fault debug help needed

[Josh Roesslein <jroesslein gmail com>]

Here is a snippet of code part of my application's UI toolkit abstraction
layer. For some reason the line of code I've marked
is throwing a segmentation fault and I'm a bit stumped as to why. I'm
thinking the way I'm passing the "this" pointer might have
something to do with the error. If you need to see additional code to help
debug this issue, let me know. Thanks!

Code --> http://pastebin.com/m6c7c97c1