I have an extreme case of this: I clicked Browse > 2D Art.

Then in the search I typed "Sci fi"

I get the same piece of art appearing hundreds of times.

I'm using Firefox in case that makes a difference.

EDIT: I have narrowed down the bug: It happens when your search term has a space in it.

For example search for "scifi" is fine, but "sci fi" is bugged. Seems to happen for any search with a space.

EDIT 2: Also it only happens when using the search box on the left, after choosing Browse > 2D.

If you search using the search box in the top right of the main page then everything works fine.