BAH HUMBUG!
I copied the recipe window WITH the WORKING horizontal scroll bar to eq2ui_mouseovericons.xml, and the horizontal scrollbar DIDN'T WORK!
The scrollbar also stops working, horizontal or vertical, if you so much as rename the page. UserScrollable="true", making sure I changed the Control on the scrollbar, nothing.
Can/has
anybody gotten a working scrollbar on a Page that didn't already have one?