wxRuby is a Finicky Beast
It's true. I've done some work with wxPython and it seems pretty stable, but wxRuby... you wouldn't even think it was the same toolkit. wxRuby typically communicates errors via a segmentation fault, so it can be a bit punishing to do development in. For one thing, the user data functions seem to be totally unreliable, to the point they've been removed off everything but TreeView, but TreeView still crashes periodically when I call get_item_data. Getting to that point, though, it's important to note that when you subclass TreeItemData, you must call super() in the constructor, or get_item_data will consistently crash, as opposed to intermittently. One other thing (and this may be a wxWindows thing) is that even though it might seem like the right thing to do, you really shouldn't use a StaticBox as a parent for your controls - just use the dialog as the parent, or layout and tabbing gets all messed up.
That said, programming GUIs in Ruby and wxWindows has been a lot of fun, if frustrating at times. The wxRuby project seems to be totally moribund, which is a shame; I really like the wxWindows environment and I'm getting to like Ruby a whole lot.