MAT Pose Edit 3 will make sure that the bump map is connected to the proper channel and that the bump strength is set correctly. I've tried it and it works pretty good, it even has a batch convert functionality that lets you update all your old MAT files (you can even chose between creating new copies or overwrite the old files). Many products have separate MAT files for P5 that loads a jpg bump map instead of the old .bum file from Poser 4. However, Poser 5 will usually still connect it to the Gradient_Bump channel, resulting in no bump effect in FireFly renders (FireFly ignores the Gradient_Bump channel). All DAZ products behaves this way. In those cases, the above trick with MAT Pose Edit comes in handy.