in display - custom poly display ...do you have border edges set to 5 and to show them ? then look at tail and see if there are dark lines then it shows it is not attached correctly ...i am not at maya right now but sure that is where to look ....happens alot when using booleans and attaching things

there should be none thick lines near tail cause it is not the end of the edge ..it needs to be joined if you see any there. .

i learned this from Happymat ... I always keep it set to 5 now and on ....

if that doesnt work can you post a pic with what is described above ?