Her mainstream American publishers dropped the series because it wasn't selling in the USA, which is pretty harsh, I know, but it's the market situation. Then the small-press Meisha Merlin picked up the series, but they went bust a few years ago, and Wurts has been unable to find a new US publisher.

She remains a decent seller in the UK, so the books are still coming out here, but American publication of the later books is apparently dependent on a new publisher picking her up and republishing the whole series, which apparently is possible but there are no firm plans yet.