Anna Grynfeld Smith (asker) Oct 2, 2010:

Thanks for your suggestions! Thanks a lot Diarmuid, but trickle doesn´t seem to work here :-D. However, I can´t choose between the other answers. Also, I asked around and somebody also thought residual would work in this context. But Sven and George; you easily beat us with your deep knowledge on the subject. So, do you mind defining (the differences between) noise, stray and residual charge? I would really appreciate it... Thanks again!