I received copies of each volume of the Isles of Glory (The Aware - published 2003, Gilfeather and The Tainted - both published 2004) in a new Australian edition. Which means folk are still buying.
And I also heard from my agent that the Russians are buying The Tainted. I was hopeful about that, having noted that my name was bigger than the title on the cover for Gilfeather (aka Smell Evil) - which is supposed to mean that the author is becoming a brand name. [And if that doesn't convince you that I am a typically anal pathetic author looking for clues to how well she is selling, nothing will...]
And if you are wondering why the Russians are buying one book at a time, well it's what happens sometimes with books that are going to be translated. The publisher has to pay the translator up front, so they like to keep the advance costs down. If they buy the whole trilogy, then they have to pay an advance on all three books. Besides, if they buy one at a time and the first book doesn't sell, they can always forget about buying the rest!