http://bugs.winehq.org/show_bug.cgi?id=3074
------- Additional Comments From imago@devinity.de 2005-26-10 10:41 ------- Created an attachment (id=1248) --> (http://bugs.winehq.org/attachment.cgi?id=1248&action=view) x86_64-fix-single-stepping-for-ia32.patch
turned out to be a kernel bug on x86_64. Patch is queued for inclusion upstream, but probably won't make into 2.6.14.