You neecd to file an amended return for 06' showing dividends paid as a return of capital and a nontaxable disrtribution.  This will require  your requesting a revised 1099 from your broker.  Attach a copy of this 1099 with your amended return.

Been there done that with IRS and finally have a rebate ot taxes in hand.  Or you can pay the taxes due now at the reduced rate before IRS returns to th old Greenspam pre-bubble tax rates.  It's your choice, but you can't really escape the tax owed.