Hi @narger,
It looks like you are not using firstMod and dcrtBits correctly. The scaling factor is given by dcrtBits. So it should be set to 30 (note that I do not recommend setting it to lower than 40 for the scenarios with bootstrapping as the precision will be very low). firstMod should be >= dcrtBits determines the maximum magnitude, e.g., if it is 10 bits larger, the message size can be up to 1024 or so.