In 2001, I was hit with an unfortunate tax bill.  I had purchased ESPP
shares in the Internet company that I worked for at a price of around
$5000.00.  The stock subsequently skyrocketed to the point where those
shares were worth more than $50,000.  Then, it plummeted and the
shares were worth $2,500.  At that point, I sold the shares.  Because
I did not hold the shares for a 2-year period, I was taxed on the
spread between the high and low values of the stock.  So, I bought
shares for $5000, sold them for $2500, and was assessed an $8,000.00
tax bill on the loss.

I was told at the time that I would be able to carry over my loss to
my 2002 taxes and receive a credit for part of the amount I lost. 
But: I neglected to file my 2001 tax return until this past August.  I
did, however, file my 2002 taxes on time.  Because I filed my 2001
return late, I was not able to carry over that loss on my 2002 taxes.

My question: Can I re-file my 2002 return (or somehow retroactively
re-submit it) so that I can take advantage of the loss carryover? 
Could I apply the carryover to my 2003 return?  Is there any way I can
still get that credit, even though I've already filed and paid the
2002 return?