poor carbination?

[longhorns]

I've never had a problem with carbinating before. I'm bottling in 1 gallon jugs w/ cork and screw cap. One of my jugs has a little foam (a small ring of thick foam). I'm thinking that I might have primed with too much sugar on that one. Or, could there be a leek in the cork and the cap? I guess I'll know when I open it, but I'd like to know before I arrogantly show off to houseguests.