Regarding the header, I think there was 4-5 instances on DSO(actual owners, though where most had it fixed independently), and a welder on Onecamonly/DSO reviewed the headers and Bisi and a staff member responded and agreed to review their welding process. I'm not sure how many complaints they got from the F/H/B guys though. The earlier models had the most problems(mine had the "weak" weld too but I sold it before ever using it). Bisi acknowledged the issue and agreed to fix all of the headers that were purchased within a year(no one knew about this "warranty" though as it was never stated or anything).
When I originally purchased my header, I had trouble contacting Bisimoto and ended up ordering through a dealer. Some small things I requested weren't done or addressed. The biggest back-lash came from their cams; lack of cam card and their reluctance to give out any degreeing information(remember, many of their cams aren't your typical drop-in and go cams). The reasoning behind this was competitors trying to steal their cam profiles.
That's kind of crappy about them not giving specs for cams, and a shitty reason too, as well as not making public knowledge of any agreement to fix a certain series of header. The real question though is ...have these problems been rectified? And are they up on CS now?