Hi,
I wonder why I've added the challenge problem spoj.pl/problems/RELBOARD/ for few days but it doesn't appear.
I checked it carefully but didn't realize any bugs. 
It seem that the following stipulation is not suitable:
"Every problem-setter can add a problem to one of the main problem-sets on SPOJ (classical, challenge, partial, tutorial), but in case of any problems with data sets, wrong problem statements (etc), Editorial Board Members are allowed to hide the problem, after that - the problem setter will see the problem for his own purposes only - but the problem will be invisible for others, and only EB Members can show it again. "
If the problem has something wrong, why don't you announce it to the problem-setter?
You just hide the problem, and it's hard for the problem-setter to find out what makes his/her problem disappeared.
p.s: My problem-setter ID: racer
