Yes, and when I tried to highlight the problem to Yahoo!
helpdesk, I get some robotic sounding reply, stating that I can
only sign in using one userid (but I only have 1 userid in the
first place).
Anyway, the problem would arise when I try to sell item directly
from my own auction page. I realised that if I take the trouble to
start the "sell item" process by clicking "sell item" from the
auction page itself (and having to select all the categories and
sub-categories), I avoided that problem.
Hope my experienced helped.