[rules-users] Compare two variables in Web based BRMS

Hi, I have a problem in the web interface drools-brms when I try to compare two variables, one of them with null value. If I try to compare with this situation, the system throws a nullPointerException, and I can't do anything. If I assign a value to this variable, the system works perfect. Nevertheless, if I do the same in the eclipse drools tool, all do perfect, and I can give a null value for a variable, because later the variable will recover the value in the program, when the rule is call. Pleased help me, because I think that it's a great bug. Lot of thanks.