if you hear a sound thru the amp when you touch the enclosure, that probably means something is shorting to ground that shouldn't be. check for any long leads sticking out on the solder side of the board and clip them close. be sure to look under the pots for long leads as well. Maybe insulate the back of the pots with some electrical tape. See the sticky called "Stephen's Tips for a Successful Build" for examples of what your solder joints should look like! Examine your board... if they don't look like Stephen's, reflow (reheat) all the joints, adding or removing solder as necessary, to make sure they look right. If you used sockets for your trannies, remove them before reheating. If you didn't use sockets and the trannies are soldered directly to the board, take care to heat them as little as possible to avoid damage from overheating. Pay close attention to your wiring at the jacks and footswitch, making sure that the wire makes a solid physical connection to the lugs underneath the solder. Trim away any long leads or frizzy ends of the wires at these locations to ensure they are only touching where they need to.
if all that doesn't work, it's time to post some pictures. I recommend photobucket as a hosting site, since it automatically resizes images for web posting and provides a one-click link for embedding.
use the copper brillo pad to rough up the "scrote" to ensure good contact