According to Firebug's net panel, the following images are referenced in wikiEditor's CSS sheets, but not present. At least one of them is causing problems (mouseover on close button in dialogs looks ugly).

extensions/UsabilityInitiative/css/vector/images/ui-bg_highlight-hard_100_a7d7f9_1x100.png
extensions/UsabilityInitiative/css/vector/images/ui-bg_glass_75_e6e6e6_1x400.png
extensions/UsabilityInitiative/css/vector/images/ui-bg_glass_75_dadada_1x400.png
extensions/UsabilityInitiative/css/vector/images/ui-icons_454545_256x240.png (close button)

Version: unspecified
Severity: minor