swim bladder disease in a neon tetra?

[featherfin]

i think one of my neon tetras has a swim bladder problem of some kind. his front end seems to be floating up and he's forcing it down. he doesn't swim nice and horizontally like the others. he is still eating well and seems to be okay other than some difficulty staying in the right position.

i tried to feed him peas but he wouldn't touch them. is there any medicine/cure i could get to help with this? i think he's had it since i got him a little while ago and i didn't notice :S