Have you tried adding \sloppy to your preamble ? This will make latex break the line before long "words".
Yes, I did try that but sloppy only justifies words on a line, and it still treats the long citation as a compound word. So although, it does alleviate the problem, it doesn't completely solve it - I'm hoping that there's some way of breaking this compound word...
Thanks for the suggestion..
nirmal
