1-click borked in FireFox and Konquerer

Somehow during a switch from Gnome in 11.1 I’ve borked .ymp file types from launching Yast in FireFox and Konquerer.

When I click a 1-click link the script text is displayed instead of launching a prompt to open with package mgr.

If I save the link to the Desktop and choose open with I get an option to open with Yast.