Canbt get comparator to work with floats

I’ve been using webMethods workflow and found that the comparator seems to work with Integers but not with floats. I’ve tried making the the constant value (the RHS) 20.0 but it reverts back to 20 when I set it. I then set it to 20.01 which held but still the ‘less than’ comparator did not work. The LHS field was definitely a float type too.

I am using workflow 6.5 on a windows XP machine. I think I must be doing something wrong here or overlooking some setting. Anyone else had this issue ?