.50% ( 4.50 % ) notes and an issuance of 4.25% ( 4.25 % ) notes for accounting purposes because the present value of the remaining cash flows plus the fair value of the embedded conversion option under the terms of the original instrument are substantially different from those of the new instrument . as a result , the 4.25% ( 4.25 % ) notes are reflected on our consolidated balance sheet at their fair value at issuance , or $ 477.0 . we recorded a non-cash charge in the fourth quarter of 2006 of $ 77