Did you start X on that connection?
I've tested it a while ago ( read as a few years ) exporting X but found not real use for this since most of my boxes are so-yesteryear-too-weak-for-real-use.
IIRC, you need to start x for that specific session ( regardless of whether your box is already running X on TTY7 or not ). It also looks like the GTK warning was of that sort. ( sorry I can't really offer specific inside of what is going on ). I'm just shooting into the dark here.