Firmware 1.0K is quite bad for W540E, I dont know why... ! I tested myself a few months ago and experienced reading problems in nero copy mode... low speed selected by default... and no cleaning problems to me.
I recomend that firmware 1.0h is the last stable
and seems bug-free version for W540E ! The 1.0K has only a single major feature - capability to read ultra-speed cdrw... no else, so it is not important in my opinion, 1.0h is better.
So, you can find it on my page at the link:
Is in the original archive form downloaded from teac.co.jp in 2002-2003 not available now... not shure when... I keep it because in the best firmware and corrects some problems. 1.0c is really old... verry old.
In the link do not work, you can try to find 1.0h on www.teac.de
in dedicated section... they keep more versions...