1) is the library ON the other nodes.
2) if it is.. is the directory structure the same... maybe the relative path is screwing you up

I mean.. the error is pretty self explanatory... perl can't find the library in your @INC...

Also... you do use lib "System/common/Bio/Tools"; then use Bio::Tools::pICalculator;
it looks like you might actually want use lib "System/common/"; since Bio::Tools is part of your module path.