Quark vertex help?

Im having a problem with Quark, and I would like your help.
Is there a way of moving vertex 2 without it changing the position of vertex 1?
I glued a face to a tagged face and it lined up nice and bonny, but then I noticed it had altered a vertex, I have tried to move the single vertex using the n key and that didn't work, I have changed the co-ordinates of the individual vertex and that moved it to the correct position but threw the other vertex out of position, I have deleted the brush and tried again and the same problem has arisen. What else can I try?

edit: img tags