i've repaired them before

http://www.youtube.com/watch?v=wsz0lNJ6JrQ

this is a good how to on repairing them but instead of the pennys i used a pencil eraser with slices cut off it slightly thicker than 3 pennys (i think i did it at 4mm)

do thins and if it doesnt work straight away the do the towel trick, i repaired one 18 moths ago and its still going strong