This new release doesn’t use GtkBuilder anymore, so the GUI problems caused by incompatibilities between GtkBuilder versions shouldn’t be noticed now.
Files are now iterated instead of being mapped into memory. This makes Meiga a little bit slower but allows execution on low memory machines, as suggested by Steven.
Meiga now also works in Karmic. Just use the Jaunty packages and they will work fine. You can get it from http://meiga.igalia.com.