Glad you found us! It's been a bit quiet on this board lately-I'm assuming it's too hot to knit.
Hmmm, this is a new one. A couple of questions about the needle-are just the ends metal, and the middle plastic? If so, I think you had the right idea with the hot water-maybe just try soaking them a bit longer, and use hotter water. In the past I've put needles in water just a few degrees below boiling, and haven't melted any yet.
If the needles are all metal, try stretching the needles out, and leave them that way overnight. If that doesn't do the trick, heat may still be the answer, but you'll need to go hotter (think blacksmith forging steel). I've never tried putting needles in the oven, but might be worth a try-just start on a lower setting. Just take the afghan off first <img src="/images/graemlins/laugh.gif" alt="" />
You might also find that after you get further along with the afghan, its weight will keep the needles straight. If all else fails, go invest in some plastic or aluminum circulars. Remember that knitting needles are like shoes, because you can never have too many sets!
Let us know how it turns out,