I have a small pencil condenser plugged into my line 6 UX2 and then into my macbook pro. when the mic is placed in the stand there is an obvious hum, but it isnt as apparent when i hold on to the mic with all of my hand. some sort of grounding problem?

what is the problem and how can i fix it?
thanks heaps.
Sometimes grounding is a problem for me too running through my board and to the laptop. Try unplugging the laptop and sometimes the cables can be an issue--not just the type but the length (don't open yourself up to EMF problems!)