Since Jenkins 1.576 (running as Windows service), some weather icons are missing. Instead, only the percentage is printed. This happens for some jobs, not for others. (it happen to be Maven jobs, I don't know whether that is relevant).

This issue started in 1.576 (where also some plugin icons in the sidebar went missing), but persists in the latest 1.577.

Note that the image apparently is loaded correctly, as some other jobs in the same percentage range get their icon printed correctly.
When looking at the html sources of the broken icons, the img tag seems to be missing the src attributes with the image filename.
Note that the same issue also occurs on the project details page, where the weather icons is normally printed at the top of the recent builds list.