HELP! Skinning problem...

Hey guys, I am extremely new to Blender, and I have a school project that
includes rigging and skinning a character. I created an IK rig, (sort of), and
automatically added weights when I attached it to my mesh. Now, though, when I
move my rig, the mesh moves properly but the clothes move slowly, making his
clothes come off…
Note that since I made my character out of multiple
meshes, before I attached my rig I had to join all the meshes (including the
clothes) together using ctrl J… could this be the problem??

This is
how it normally looks…

http://i.imgur.com/7tVAn.png

This is the moved arms…

http://i.imgur.com/ctt4c.png

And this is the moved
legs…

http://i.imgur.com/bZULN.png

HELP!!

well, there are a couple things. one is you could try using the shrinkwrap modifier instead of weighting the clothes. another thing you could do, is us corrective shape keys, which i find very handy. and the other thing would be careful reweighting of the problem vertexes.